4.8 swap?

[T/A Addict]

Is anyone doing a 4.8 swap or is the little guy just not worth it?

[andrewb70]

Is anyone doing a 4.8 swap or is the little guy just not worth it?

As swaps go, all things apply to a 4.8L as it does to any other LS. Whether it is worth it or not is entirely up to what you want. If you want 500hp, the 4.8L is not going to do that, unless you add boost.

I have a cam only 5.3L in my Cougar and it makes about 325 rwhp.

Andrew

[68Formula]

Depends on what you want and what you're putting it in. It's basically a short stroke 5.3L. It wouldn't be a torque monster. But with just a properly chosen cam, long tube headers, a tune, and the proper valvetrain, you could have something NA that makes 325-350rwhp that likes to spin to 7k.

Or as Andrew said, it'd tolerate quite a bit of boost. Add an intercooled supercharger or turbo(s), and 500+rwhp is possible.

[T/A Addict]

Thanks guys..... I'm not a drag strip guy, just wanting to make a super fun street car that I would love to road track if given the chance.

Here is where I am at, I'll give you this info and get thoughts...

I have a 79 Trans Am that is currently frame-off, I have the subframe ready to reinstall, it has tubular arms, coilovers, CAT 5 rear leafs etc.
I was planning on a 6.0/6 speed but....

I also have a 69 Firebird that I just pulled a Chevy 350 out of and was about to put Pontiac 400/350 auto in it just to make it drivable and enjoy for now but going pro-touring/mini tub in it eventually.

I recently purchased 2 400s, 1 freshly built to install now and 1 in need of a rebuild, thought a stroker 400/6 speed would be great in the 69 but now I am here at this point... I have a chance to pick up a 4.8 so now my thought may be changing to going with the 4.8/6 speed and maybe turbo in the 69 and going 400/6 speed in the 79. Thinking that the 4.8 would be happier in the smaller/lighter 69....Decisions decisions......

[Afflicted1]

https://www.google.com/amp/s/www.hot...ng-theory/amp/

[ProTouring442]

As swaps go, all things apply to a 4.8L as it does to any other LS. Whether it is worth it or not is entirely up to what you want. If you want 500hp, the 4.8L is not going to do that, unless you add boost.

I have a cam only 5.3L in my Cougar and it makes about 325 rwhp.

Andrew

Not to hijack someone else's thread, but what cam?

[andrewb70]

Not to hijack someone else's thread, but what cam?

I am using the GM ASA cam.

Andrew

[badazz81z28]

The cost for a conversion is the same regardless of the Cubic inch....no reason to go small. The cost difference of the engine itself is the only factor.

[dontlifttoshift]

.....especially when LS7s are 4500 bucks.

[T/A Addict]

.....especially when LS7s are 4500 bucks.

Ha.... that is funny

Engine is the only cost difference, I can get the fresh 4.8 without intake for about 400. This is the only reason I am even considering it otherwise I'd prefer a 6.0 any day.

[andrewb70]

What sort of chassis is this going into?

Andrew

[T/A Addict]

This would be a stock 69 Firebird

[andrewb70]

This would be a stock 69 Firebird

What are the goals for the car? Honestly, I think a 4.8L would run circles a stock 400...and for sure a stock 350.

Andrew

[T/A Addict]

My ultimate goal with the car is a super fun street car, 6 speed, mini-tub and light pro-touring setup. I am not crazy enough to think that I will ever have the money to build any where near the badest/fastest car but I am more than happy with a car that performs and handles quite well just to enjoy some spirited driving and maybe some track time if given the opportunity. Thus the thought of a 4.8 turbo build.

[andrewb70]

If doing a 4.8L now will get the car on the road sooner, then do that. You can drive it now and slowly upgrade power. Either by adding a turbo or going with a more displacement in the future. Once the swap is done, it is relatively easy to swap different engines in place of the 4.8L. I'm a fan of gen 4 engines, so I would lean towards a gen 4 4.8L. This way you can swap in a LS3 down the road without major changes to the electronics.

If you go with something like the Holley HP EFI, that will give you the flexibility to do your own tuning and the ability to run either a 24 or 58 reluctor engine. Plus the Holley is better suited for forced induction.

Andrew

[Kenova]

I don't know how relevant this is, but I have a 4.8 in my 2013 1/2 ton with 3.73s and an auto trans. It will wind up like nobodies business. A 4.8 with a 6 spd. in a first gen. would be a blast to drive.
Like Andrew said, once it is in, the ground work for a bigger engine is already laid.

Ken

[DualQuadDave]

in the drag world, the 4.8/5.3's are king w/ boost due to the thick cylinder walls and lack of windows in the mains. Stock blocks can hold 1200hp w/ prep, sometimes more. If boosting, keep it, if going on motor, go 6.0/6.2 and don't stroke it. Really depends on ultimate goal. FYI, all LS's cost the same to build in the end. The whole "I got a great used xxx for nothing" is going to come to end sooner than later. All the used stuff is mid 6 digit mileage and will need to be gone through to survive in th long run. I know, I build them.

Edit: when you cam it, remember it's tiny. Going big on the cam will dyno great and be a complete pain in the ass when driving. Think [email protected] on the intake and go with a fairly narrow love sep like 110-112 to keep the torque up through the mid-range. Cathedral heads all the way, 243/799 with just a bowl port.

[Btamayo23]

I put a 4.8 4l60e in my friends stock suspension 67 el casino. It's a blast to drive way more power and more reliable than the 305 that was in it. Iike someone said earlier if you find a 5.3 5.7 or 6.0 down the road most of the work is done. If you're not sure what cam to use dont forget the forum sponsor Texas speed has always been super helpful and knowledgeable in everything they've recommended for me. I currently have their cams in 2 different motors. I think you'd be happy with the little 4.8.

[T/A Addict]

Thanks for all the info guys.... many points well made, especially the fact that as swap to a bigger motor later would be easier if wanted.
Good point on the cost of rebuild being all equal Dave and thanks for the pointer on Cam, comes with 862 heads with a .010 surfacing, any good?
Just to start researching options now, cam, intake etc. and start pricing how much a turbo will cost me so I can decide if that comes now, later or at all.

[DualQuadDave]

Dont put $1 dollar into the 862 heads. The best bang for the buck are some 799's. PM me contact info, will help you build a combo and give some insight. The typing kills me, lol.