LT1 swap, should I?

[Johnny Blaze]

Here's the deal. I have a 1971 camaro. The build plan is mild pt/ driver.
It currently has a tired 1990 350 truck motor with a performer intake, 600 edelbrock and headers.
On my daily commute, it averages 16mpg.

I would like to build a new engine, with a goal of 400 flywheel hp, or close, and to get milage up to at least 20, with a goal of 25mpg.

I could rebuild the 350, and a roller cam, vortec heads, however, I have access to a complete lt1 and 4l60e, wiring, ECM, etc from a roadmaster.

For the same money I can rebuild the lt1, and already have efi.

I know in the days of lsx, an lt1 swap seems silly, but in reality I can accomplish this for thousands of dollars less than a lsx swap.


So, any advice?
Will the lt1 meet my goals?
Anything to look Out for if doing such a swap?

[Mr.VENGEANCE]

is the lt1 free?

[CapSS92]

I used an LT1 from a Roadmaster also in my 65 Chevelle with a Tremec 5 speed and stock 3.31 gears. It was pretty easy to do and like you said, a lot less than the LSx conversions. That being said I have a junkyard LS1 that I will eventually rebuild and install, as time and money allows. I used lt1swap.com for the wiring info and it fit pretty easily into the car. I used a set of SBC long tube ceramic coated headers that I had laying around and they've worked fine. The car runs pretty fast and I use it as a daily driver. 11k miles and no major issues. Don't scrimp on the waterpump and Optispark. Got them from Autozone with the lifetime warranty as I used a cheapie Optispark in the beginning and it would die after running for 30-45 minutes. Changed it to the Autozone one and it's worked fine since. I had the software and equipment to reprogram the computer so I fine tuned it to my needs. You can actually drop the MAF thru programming if you want a cleaner look. As for mileage, I get about 14-15mpg in the city. I think a lot of it has to do with the Flowmaster mufflers. I can't seem to take off normally from every stoplight. <g> Damn roar of the exhaust gets me going every time. <evil grin> If I had a lighter foot I could probably do better on mileage but then I wouldn't be as happy driving the Chevelle. Oh almost forgot. Mounting an AC compressor is a hassle. It seems you may have to notch the frame if you use a stock AC compressor. Forget about aftermarket solutions unless you want to go with an Alan Grove setup or something similiar. It kinda negates the low cost aspect. If you're not running AC you can use an AC delete pulley. They run about $40-50 on ebay. I used one so that I can always find a stock belt at any auto parts store. Hope this helps.

Alex

[Johnny Blaze]

Yeah, after scraping the car, I should come out with less than $300 in the entire setup.

[Johnny Blaze]

As much as I would love to build an lsx, cost is just too much for me, either way you go. Or end up with a used assembly.

Basically, I can rebuild my smallblock, and tune the heck out of a carb, or spend $1000 on efi,
or for nearly the same cost, rebuild the lt1 and already have efi.

Or I just install the 12:1 427 and say screw mpg!

[CapSS92]

I personally like EFI. It starts everytime I turn the key and I don't have to worry about messing with anything. I'm not a carb guy and I had a really hard time when the Chevelle had a carb. There's no warm up time with the car and the loud mufflers give me plenty of old school muscle car feel for me. Plus I like the modernization aspect of it. I've also installed a mirror that autodims and has a built in garage door opener, the trunk is electric, I made my version of the DSE multispeed wipers, the instrument cluster is from a 95 Camaro so I've got all the gauges working including the warning lights, the windows are one touch electric, and I don't use keys to turn on the car as I built an RFID system. I use a little key fob to activate the car. So the efi fits. LOL.

[CampbellshotrodsAZ]

I'm pretty much doing the same thing with my 67 Camaro. Several months back I got a 97 Trans Am with 90k miles that was slightly tweaked. Bought the car, parted it and got all my money back. I'm going to use as much of the T/A stuff as I can, including trying the pedals as I've gotten to like the pedal positioning in my 98 T/A. I like the LT1 in that it will bolt right in, other than the A/C compressor. I figure for this kind of racing I don't need insane horsepower, at least more than I will have to worry about building this LT1 to non-emissions compliance. After it proves itself it'll get heads, intake, and cam. The LS1 is a great motor, but I'm actually looking forward to the LT1 swap as it will be something different, and I'd like to show it to be a worthy powerplant.

[minendrews68]

Dang capSS92 I believe we need to talk.....

Carl

[CapSS92]

Sure Carl, always glad to be of help to the community. I used to convert LT1 93-96 Camaro clusters for the 94-96 Impala guys back in the day. I like the look of them plus it fit right into the Chevelle's dash. I like to use as much stock stuff as I can so I can always get replacements easily. The local Pull-a-Part is my second home. :)

Alex

[alocker]

Rebuilding the LT1 is is where a junkyard ls starts to catch up. The lt1 is great, I have swapped one myself but spending the cash to rebuild would be a deal killer. I would rather find a nice running 6.0 and throw a cam in it.

[130fe]

Alex, like that gauge setup! I also just put in a gentex rear view mirror with auto dim, compass, temp and garage door opener. I am trying to update my car to newer standards as much as I can, not much 68 left in my car LOL

I used to have an LT1/4L60e until I recently swapped in the LS3. As a cruiser car, it was fun to drive and very dependable. In the end you just have to make sure what you want out of your car. If you are looking for a 400rwhp car the LT1 might not be the way to go. I had a hot cam in it and it was a great engine that got 20 mpg and I had no issues doing a couple of Power Tour long hauls.

The LT was ok but the aftermarket is nearly non existent. A stock 5.3 puts out about the same power as my hotcammed LT and you can do a lot more with the 5.3. Are you converting the wiring yourself? The fuel system for both engines is about the same. If you have to rebuild the LT, then I would recommend the LS series.

[130fe]

One other thing to consider is are you positive you have an LT1? Some of those cars had a L99- the 4.3 version of the LT1. Externally they look identical. I think you can check one of the digits of the VIN. Wouldn't want to go through all of that trouble for a 200hp 4.3.

[Bonehead]

As far as I'm concerned, the only LT1 that exists can be found in new Corvettes and Silverados. To which I'd say, HELL YES SWAP IT!!!!!!!

;)

[Johnny Blaze]

Rebuilding the LT1 is is where a junkyard ls starts to catch up. The lt1 is great, I have swapped one myself but spending the cash to rebuild would be a deal killer. I would rather find a nice running 6.0 and throw a cam in it.

But then your comparing a fresh rebuilt lt1 cost, to a used unkown ls.

With a junkyard 6.0, I'd still have to get the proper accessory drive, oil pan, intake, ls specific trans, mounts, headers, etc


Truely price a junkyard ls swap, you ain't doing it for $2k like people often think.

[alocker]

But then your comparing a fresh rebuilt lt1 cost, to a used unkown ls.

With a junkyard 6.0, I'd still have to get the proper accessory drive, oil pan, intake, ls specific trans, mounts, headers, etc


Truely price a junkyard ls swap, you ain't doing it for $2k like people often think.

You are absolutely correct. There is also an unknown even with a newly assembled rebuild. Finding a used LS from a reputable seller is pretty easy though.

You have to really ask yourself what your end goal is. My first EFI swap was an LT1 with a CC306 cam and ported heads. It was a fun car but in the end I wanted more and I ended up swapping in and LY6 6.0. I would have saved a bit if I had done the LS swap first. If you know 100% for sure you won't want anything else, the LT1 is a great choice and very reliable. The big problem is rebuilding a motor the right way is expensive. I know a whole car for $300 sounds like a great deal, but you have to make sure it's what you will be happy with long term.

[Johnny Blaze]

I am trying to keep this a mild driver.
I'm finishing up the 55 bel air with a 8/71 blown BBC, so I don't need two cars with huge hp and poor manners.

As stated in first post, goal is drivability and milage.

Adding all up, rebuilding lt1 is still cheaper than swapping a junkyard ls, so budgetwise gen 1 or lt1 are my best options.


No ac so I don't have to worry about that clearance issue.

Later if I got tired of the lt1 power and wanted big power, it would be easy to drop my built 427.

I'd love to build an ls, and have weighted the options, turbo 5.3, lq4 with l92 heads,etc....

But cost still adds up temendously with ls swaps, even with junkyard parts, and you have just that, a used junkyard engine.

[jasonsnova]

gotta say your mpg wants are on the very high side for a lt1, this project screams ls/ junk yard 5.3! 5.3's can be had dirt cheap, get one complete with accessories, maybe swap in a cam and your gonna be where you want to be on the cheap.

[Johnny Blaze]

20-25 mpg is very high for am lt1?

I get 16 out of a tired carbed 350 without od.

An lt1 with od should get better, I would think.

[NJSPEEDER]

LT1's don't get the mileage of the LS motors. Better than a carb but not by a lot.

Honestly I would rather do a gen1 engine with aftermarket EFI or an LS motor than deal with the LT1. For the grand or so more you will end up spending on either you get a vastly more reliable ignition system and tons more aftermarket support. Not to mention how much dropping 100+ lbs with an aluminum blocked LS will do for mpg and performance.

-Tim

[NJSPEEDER]

The cheap path to an LS conversion is buying an old f-body. The engines are good for tons of miles so even if it has close to or a bit over 100k on it you will have several years of service left. Part out or use the bits you don't need to recoup costs and pay for the aftermarket parts you need for the swap. Just look around craigslist or any f-body site to see what people are getting for trim and other parts.

[Johnny Blaze]

I can rebuild the lt with a mild cam and everything for $3000.

That would give me a complete new, balanced engine.

Show me the way to do am ls swap for $3000.

I've been watching for ls motors or cars in my area. Even a 5.3 iron longblock goes for $500 plus.

[CampbellshotrodsAZ]

I wouldn't put too much faith in a junkyard LS even. I've had enough of these apart, and known enough people to have issues with the stock pistons, such as a broken ring land on a used engine I got. Even if I got a used LS I wouldn't have much confidence in it without upgrading the pistons and rods. You'll be bulletproof then, but that's more initial cost, and not quite a junkyard build anymore.

[Johnny Blaze]

^ agree.

I want a fresh engine that I know will last. Sure I would love to build an ls, they are awsome, but budgetwise I think you get into the law of diminishing returns.

I just can't spend the 6k plus it would truely take for an ls swap.

So it's really, rebuild the gen I, but the lt1 or say screw it, throw in my wicked 427 and kiss mileage and highway driving goodbye.

But like I said, I have thr blown 55 for that.

I just want the camaro to be a car I can drive across the county and not go in debt from gas.

[CapSS92]

My LT1 costs $300 and it had 100k on it with semi decent compression on one cylinder and after 11k miles I still enjoy the heck out of it. I did replace as many gaskets as I could as well as the oil pump. I say put it in as and enjoy it. I waited for an LS1 to come along as sure enough a new LKQ pull a part opened up and I scored an LS1 from a 2000 Camaro for $150 bucks. I'll rebuild it as time allows and install it in somewhere down the line. But for now the LT1 works great and it gets me to work on time. :)

[camrat68]

One other thing to consider is are you positive you have an LT1? Some of those cars had a L99- the 4.3 version of the LT1. Externally they look identical. I think you can check one of the digits of the VIN. Wouldn't want to go through all of that trouble for a 200hp 4.3.

The wagons only came with LT1's. If it's anything else then it was swapped which is entirely possible.

https://static1.pt-content.com/images/pt/2014/09/th_crankinstalled1-1.jpg (http://s39.photobucket.com/user/95SStorm/media/crankinstalled-1.jpg.html)


https://static1.pt-content.com/images/pt/2014/09/th_PC3139401-1.jpg (http://s39.photobucket.com/user/95SStorm/media/PC313940-1.jpg.html)


These are the LT1 casting numbers. They are located between the freeze plugs and above the knock sensors on each side of the block as well as behind the drivers side head. The cast in number behind the head on an L99 engine will say 5.0 instead of 5.7.

Jim

[CapSS92]

As far as I know all Roadmasters, wagons, and Cadillacs for 94-96 only came with LT1's. The Caprice sedan had the 4.3 option. So if it's from a Roadmaster you should be good.

[MonzaRacer]

LT1 is a great engine. Iron heads are little under whelming but even scrounging up a set of Vette aluminums isnt that hard. I have even seen a few older aftermarket LT1 type heads.
BUT take any of the heads, swap in some one piece swirl polished valves, do a throat and polish job, gasket match.
They are basically on bottom end like an L98. Only issue is three different balancer adapters, two different balancer basically. Adapting accessories just takes a little ingenuity.
Add some basic hot rodding tricks, squaring, bore/hone with torque plate.
Add some Eagle rods, good forged pistons make solid bottom end.
I am using LT1 intake on my 283, my intent is to use DIS from a Northstar V8. This is so I wont have to mod my intake for a distributor.
I also intend to run the LT1 oil pump drive and mod it for cam sensor duty.
To run any engine, depending on basic needs you can run one of these on an old Gen1 OBD1 computer from L98.
The basic information from a GM DIS module is same as HEI so I wont have much integration issue.
You could also use basic crank trigger, or the Optispark also works well.
A basic, well built 4l60/700r4 are simple to build/setup and will give great service and mileage.
An LT4 HOT roller with 1.65 roller rockers comes in at .541 lift, and can run with a little as the stock 1.5 rocker which gives .492 lift. I ran mine with a TCI Saturday Night Special, running it hard with Qjet jully dialed in and 2.73 open rear end and TH350 it averaged 14 mpg local and 18 mpg on power tour. And I ran hard to keep up with Illinois car club that was pushing speed limits.
Figure 22-24 mpg with 3.23-3.55 gears and overdrive.
If you want FI, you could use Megasquirt or even Microsquirt, thats what I am looking at if my GM pcm idea fails.
Or was my plan all along.
The LT1 was great engine, could hold its own and other than few parts are loads cheaper than LSx. Minimum out lay is $500+ engine, minimum $1000 for ignition, headers. Mounts, accessories and upgrades all take MORE cash.
Even a ball hone, rings and bearings can be done cheap even using stock pistons and rods, and any 350 piston rod combo for most part works just fine.
To all who have the love of LSx, go for it, if you have the cash, rock on but not everyone can do it. I have seen guys throw up their arms and sell projects and quit over the cost of doing LSx conversions.
and they could have had cars running for much less if not nearly free with simple sbc swap in. Intakes and headers all over, Ignition is a trip to Autozone or Advance, etc. Headers also. Trans will work from just about any year GM out there and it doesnt take sending anything out or spending large dollars.
Heck I am either two wrist pins or two pistons away from having 90% of my engine parts. Basically cam kit, gaskets and rings other than pin or pistons I need. I even have another pair of carbs, two or three ignitions, two sets of headers if I dont try to build my own stuff right off for turbos, or the turbos.
Figure $500 would put me into car, with nearly running if not running engine, on a carb.
Heck just replacing tires with same size a I ran on my other Monza would hurt worse. As would tires on Caprice.

[Johnny Blaze]

Thanks for the info Lee. Although everyone I've talked to says the iron lt1 heads are actually better than the aluminum ones.

Lots of good info so far, we have heard from a few people who have actaully done a lt1 swap with good things to say, a lot of people saying go ls, which is a better engine no doubt, buri have not heard much good reason not to use the lt1.

Again, if I had 6k to spend an lt1 would not even be considered, but I don't, and. I don't want to wait 5 years until I could afford it.

Not too mention 71 camaro's came with the bad ass lt-1 ;) so I'm kinda keeping it stock :) (:

thanks for everyones input so far and keep it coming!

[MonzaRacer]

Either head can easily support 400-450 with good old fashion port, polish, and throat job, valves/springs. Throat job is where I cut a gentle curve on stone I use. The stone diameter I use for this practice is same diameter as inside edge of the valves ground face. This was how I set up dirt car heads locally, I also raised guide spotting buy 3/32 with guide facing tool. Flow numbers on old stock cast heads all seemed to go up and all had great results.
Now these are really maxed out but can lay down solid numbers if paired with right cam.
I really hope to locate on of these and do some playing with one, and actually hope to locate a 5.7 AND 4.3 so I can build an LT1 302! Namely cause a buddy has a set of what are supposed to be AFR LT1 heads and some version of FI intake stashed.
But till I win lottery and have lots of cash Ill keep up with my older sbc stuff I own.
Good Luck

[Nophix]

I am trying to keep this a mild driver.
I'm finishing up the 55 bel air with a 8/71 blown BBC, so I don't need two cars with huge hp and poor manners.

As stated in first post, goal is drivability and milage.


Adding all up, rebuilding lt1 is still cheaper than swapping a junkyard ls, so budgetwise gen 1 or lt1 are my best options.


No ac so I don't have to worry about that clearance issue.

Later if I got tired of the lt1 power and wanted big power, it would be easy to drop my built 427.

I'd love to build an ls, and have weighted the options, turbo 5.3, lq4 with l92 heads,etc....

But cost still adds up temendously with ls swaps, even with junkyard parts, and you have just that, a used junkyard engine.

If you want to keep it a reliable driver, save for the Ls swap. The LT1 has a lot of potential, but they are very picky engines. Most of the issues stem from the Optispark distributor. I've built several, and have one currently, but reliable is something its not. It's also getting very hard to source Good Optis. Even the expensive MSD is hit and miss.

And yes, you can hit ok mileage wi them. My current z28 is getting about 24 hwy with 3.73's and an auto, my last Firebird was a monster, with 3.42's and a 6 speed. I got 26 with that.

Hat being said, by the time you get it sorted out, you would be into it for as much as the Ls.

[nekkidhillbilly]

One other thing to consider is are you positive you have an LT1? Some of those cars had a L99- the 4.3 version of the LT1. Externally they look identical. I think you can check one of the digits of the VIN. Wouldn't want to go through all of that trouble for a 200hp 4.3.

and any built before 94 had tbi engines basically the same engine in your 90 chevy but they all had a 350 block lt1 or tbi no 265s with.

[AdvAutoBob]

nothing wrong with an LT1 at all.. They're great little engines, properly prepared. I had one in an '85 Corvette that ran high 10's at the strip, (through full exhaust), and still had power everything and A/C. I embarrassed a lot of LS guys with my "junky old LT1" ;)

https://static1.pt-content.com/images/pt/2014/09/Firebirdnitrous2_zps10b0f54b-1.jpg

This one's going into my '80 Firebird project, along with Vintage air, etc., and it's designed to be a driver.

Only real weakness of the LT1 is the junk powdered metal connecting rods that GM put in them, but LS engines have those too.

I'm not knocking LS conversions at all (doing an LS6 in my '67 GTO as a matter of fact), but in this case.. use what you have, put it together and drive the wheels off it!

[jasonsnova]

I can rebuild the lt with a mild cam and everything for $3000.

That would give me a complete new, balanced engine.

Show me the way to do am ls swap for $3000.

I've been watching for ls motors or cars in my area. Even a 5.3 iron longblock goes for $500 plus.

Ok...my nova.
Bought a used 6.0 with 10k on it for $800, was in a side impact collision one of the manifolds was broken and they were not sure of condition of head. I took heads off sold them for 150 (they were fine) bought last heads on ebay for $800. Intake (carb) msd box $750, headers $450, engine mounts $75, Texas speed cam $400, new springs $200 sold new ls3 spring go for $50, head gaskets $40

So for a Lil over 3k I have a 530hp ls motor.....build that kind of hp in a small block for that kind of $$. I know I had a lot more than that in the old Gen 1

[Johnny Blaze]

^ sounds like a fun engine! Any idea what mpg it can get?

[nokones]

If anyone is interested, I am taking out an 1989 SBC 350 .030+ L98 engine and ZF 6 Speed Transmission out of my Corvette and both items are for sale separately or as a package. The ZF tranny is stock and the engine was built for autocross events. Lots of low-mid range torque. The engine has very little time and only has been autocrossed. No highway miles. The engine is equipped and will be sold as a complete engine unit with AFR Heads and Rev Kit, Lingenfelter Super Ram (Box) Fuel Injection and Throttle Body, Comp Cam, Mahle Pistons, Scat Crank and Rods, Aluminum McLeod Fly Wheel, and starter. The engine will produce 363 Horsepower/396 Torque at the wheels. The engine will not include the distributor, Water Pump, Valve Covers, and drive pullies. The transmission will include the McLeod Clutch Assembly and bell housing. This is a single mass clutch with the pull actuation.

Dyno sheets and photos available

The package is for sale at $5,000. Separately, the engine is $4,000 and the transmission is $1,500.00. Buyer pays for the freight or can pick up the item(s) in Grass Valley California.

Please email me at [email protected] or call me at (530) 742-9000.

[jasonsnova]

^ sounds like a fun engine! Any idea what mpg it can get?
Don't know....my previous 430hp gen1 sbc with 411's t56 6 speed and a gas guzzling holley he double pumper carb managed almost 20mpg. Being these engine are far more efficient I expect the same or better but more power and better drive ability

[MonzaRacer]

Ok...my nova.
Bought a used 6.0 with 10k on it for $800, was in a side impact collision one of the manifolds was broken and they were not sure of condition of head. I took heads off sold them for 150 (they were fine) bought last heads on ebay for $800. Intake (carb) msd box $750, headers $450, engine mounts $75, Texas speed cam $400, new springs $200 sold new ls3 spring go for $50, head gaskets $40

So for a Lil over 3k I have a 530hp ls motor.....build that kind of hp in a small block for that kind of $$. I know I had a lot more than that in the old Gen 1

Yeah but if he has a LT1, its done deal. Ball hone and basic rering kit gets short block read, no extra mounts too buy, most sbc headers can be ran or modified to run, uses regular SBC one piece rear main oil pan.
Figure this one anywhere from $500-$1000 max on long block if you shop around and that is dependent on amount of machinework done and forged or hypertech pistons, and maybe a plain old set of Eagle I or H beams, you can probably have no more than $1500 in assembled engine and STILL have decent power. Find a deal on an LT4 HOT cam and even with stock rockers it makes a GREAT package. My truck never wanted for power and I even had it running with STOCK converter, but a TCI Saturday Nite Special is about perfect for that cam, had one in my TCI TH350 in 71 Monte Carlo and had one behind my big block too.
And if you get inventive you can dump the Optispark and modify the intake and use a small cap TBI distributor. Really doesnt need LT of work to get it in there. And if you run something like that you can even use older TPI style computer.
I actually have a 93 TBI S10 4.3 computer and harness and have toyed with simply adapting THAT and reprogram my own prom
I keep hearing about how great LSx junkyard swaps are and seeing so many just literally falling apart after abuse.
I have beat on too many SBC with no ill effects and my buddy had an old used 283 he dragraced for years, still running when sold, guy pulled it apart to rebuild and 7 pistons fell apart!
I have seen too many low miles LSx have catastrophic failures. For $3k I can make what all the LSx proponents call old junk run pretty dang good! And you can swap on a carb/intake/HEI and DRIVE.
No special parts. and pretty much all would already be roller cammed so all you need is new cam and new mellonized dist gear.