71 Chevelle 408 LSX build thread

[Chevelle598bb]

Hey guys, I am finally getting around to making a build thread for my ole chevelle. I have owned it for about 13 years now and it has been everything from a daily driver to almost a true street 10.5 tire car. The only thing I lacked to run the car was a roll cage. But ofcourse we all make a few passes without the required safety equipment. After years of drag racing it started to get old and too expensive to run true street so I decided to try out the pro touring scene. I am already well into the conversion so I will try to fill in all of the blanks from the start until know. Before I started the conversion this is how my car was set up. I ran a 468 with ported 990s, solid roller, 630 hp/530 ft lbs, 10.5 to 1 compression, set up for juice, Th350, 4000 converter, 4.56s, bfg drag radials, moser m9 rear end, and stock malibu dash and interior. I was running stock style suspension, ofcourse adjustable rear control arms, moroso trick springs all around and adjustable shocks. The car launched straight, drove ok and was fast. For brakes I was running 10.5 gm metric brakes up front, 11.5 ford explorer rear disc brakes, and manual disc master cylinder with 7/8 bore. I could drive the car anywhere without worry about breaking down or overheating but as some know solid roller big blocks are hard on valvetrains. Also not to mention the brakes were not the best set up and the suspension was not to impressive in the handling department. So not to long after I finished the car I decided to completely redo the car in pro touring fashion with some persuasion of a buddy building a pro touring 73 camaro. Here are some pics of the car before I tore it back apart.

[johnny68]

looking good will be a nice pro touring car keep the pictures coming
john

[Chevelle598bb]

I started my pro tour conversion with the brakes first. I purchased a new set of factory disk brake spindles and a set of Kore3 C5 brake brakets. I also picked up a set of Z51 rotors, new C5 calipers, ceramic pads and new hardware. Ofcourse the draglites would not fit with the new C5 brakes so I picked up a set of C5 black Z06 wheels. I had 295/45/18 in the rear and 275/40/18 in front. I was planning on throwing in a hydraulic roller in the big block and keeping it. For a trans I was planning on a T56 to put behind the big block. I took the 4.56s out of the rear and replaced them with 3.25 richmonds. I kept the detroit locker and 35 spline axles in the m9 rearend.

[Chevelle598bb]

Before I tore into the big block I caught the LSX bug and had big plans of a turbo lq4 and T56. I got an LQ4 and started mock up. I also picked up a Borg Warner turbo. A few weeks after that I got a killer deal on a new 408 rotating assembly and new LS3 heads. So I ditched the turbo set up for the big cubes.

[Chevelle598bb]

After mocking up the motor and trans, and ditching the turbo idea, the next line of business was the suspension. I was going to re-use the adjustable control arms in the rear and stock control arms in front with air ride cool ride in the front and rear. I already had all of the air ride set up and wanted to use it since my garage is not very flat and the car scraped every time I pulled it out. Then I came across an amazing deal on a new set of upper and lower front global west control arms, lower rear spherical bearing tubular arms and a set of baer anti bump stop tie rod ends. With the global west front lower arms you have to use a shockwave instead of the cool ride set up. Well 1300 bucks was not in the budget for shockwaves so I held off on the air ride for now. Up front I have Afco 650 lb 5x9.5 springs with heavy afco steel shocks and adjustable spring cups and in the rear I have performance online 3 inch drop springs that are 225 lb with afco medium steel shocks. For now I am running the stock front sway bar and none in the rear until I get some track time for tuning. I may switch to Afco pigtail rear springs with adjustable spring cups to lower the rear a bit. I also traded my knock off Z06 wheels for a set of C5 speedlines. One reason I traded was the 275/40/18 on a 10.5 wide wheel up front was a very tight fit. It would have worked if I did not run front wheel wells but I plan on doing so. I also picked up a Iroc steering box to replace the manual box I was running. I have been looking at some TSW Valencia wheels to throw on after I get it running with the tire size I would like to run. They are made for BMWs but have the correct offset I need and the bolt pattern is within .6 mm. The widest the wheel comes is 9.5 inches so I cant run a very wide tire but it will get close to what I want. I plan on using a 295/35/18 on the rear and a 255/40/18 on front. Then later down the road I will buy a set of forgeline, boze or other real pro touring wheel.

[Chevelle598bb]

Now that the suspension is finished, I am now moving to onto the motor and trans. The motor is 408 ci, iron LQ4 block, ARP main studs, .030 over, align honed, Eagle forged 4.0 stroke crank, Eagle H-beam 6.125 rods, Diamond L92 pistons, F body oil pan, Corvette LS3 balancer, Melling oil pump, 2007 LS7 camshaft, LS3 heads, Comp 918 springs, trick flow pushrods, Comp billet timing set, factory rockers, LS7 lifters, Corvette accessory drive and GMPP single plane intake. When I purchased the LS3 heads, they came with a new LS3 intake. I was planning on using the intake but really want to use a factory cowl induction hood with a factory air cleaner. That would mean I would have to switch to a single plane intake. I then came across a fellow who wanted to trade so I then had my GMPP single plane. I then picked up a Holley billet 4150 throttle body. I kept the LS7 injectors I already had and made some brackets for the LS3 billet fuel rails I already had to work with the single plane. I know its kind of a mix and match of parts but I want a reliable and efficient motor with a stock style idle. It should make plenty of power and torque for what I plan to do with the car not cause any issues. I know I am leaving some power on the table without having a custom cam ground but I think the LS7 will do what I need it to do. For the trans I am using a LS1 T56 with a LS7 clutch/flywheel combo. I have the motor and trans mocked up where I need them but I still need to make a trans crossmember.

[Chevelle598bb]

I still have quite a bit to do to the car such as clean the frame and repaint it, smooth the firewall, repaint the car, assemble the motor, rebuild the trans, finish building the engine wiring harness, dynamat the floorboards, install my covans gauge insert, make a wiring harness for the autometer gauges, get the GTO taken off my 06 GTO seats, and install the vintage air set up. I am also on the hunt for a set of headers for the car. I had a set of LS3 exhaust manifolds from a vette but they did not come close to fitting. So I am looking for a long tube header that will tuck close to the floorboard and not drag the ground. I like the edelbrock swap headers but they do not make them anymore. I will probably end up using a f body header such as a super comp or edelbrock victor due to their 1 7/8 primaries and equal length. The price of headers are just outrageous lately so whatever I can fit into the budget is what I will use.

[Amatouring]

Nice Car! you are going to love driving that thing when it is finished. I have the Edelbrock headers on my 72, and they fit great, but are still the lowest point on the car so they limit how low I can set the ride height. Please keep us updated on what header you use and how it tucks to the underbody. Are you also using the GTO rear seats? I loved the seats in my 04 GTO and have considered adding them to my 72 Chevelle.

[Chevelle598bb]

Yes I am going to use the gto rear seat also. I am going to cut 3 inches out of the bottom portion of the back seat to lower it. Then just place the stock leather cover back on it. Then I will have to make some filler panels to fill between the rear seat and rear door panel or make a new center section to the rear seat and space the buckets out. Not sure yet.

[Motown 454]

Nice looking set up.

[6D9 Matt]

Very nice man... good build. Subscribing...

[Chevelle598bb]

Well there are a few small changes coming for the car. I decided to lower the rear of the car another 1.5 inches and about another 1.5-2 in the front. I have about 7 1/4 inches of clearance at the lowest point of the outside frame and about 6 at the crossmember. So down it goes. I think it will look better to with the shorter tires. I also hashed out the A/C system finally. I am going to use a vintage air sure fit kit with a sanden compressor. I wanted to mount the compressor in the stock location. John 67 on another forum made some brackets a few years ago and sent me the templates. It moves the compressor forward to run on the main belt drive. It works with the C5 and C6 ls1,ls2,ls3 accessory drives. So now I get to play with the CNC plasma table!

[Chevelle598bb]

Also the bracket keeps you from having to notch the crossmember for clearance.

[bhcustomdesigns]

nice car cant wait to see it finished!!

[FRENCHBLUE72]

Sounds like she is gonna be a fun ride when its all done..

[Chevelle598bb]

I traded back for my knock off Z06 wheels. I just did not like the way the C5 speedlines looked on the car and the front tire just looked too small. For now I will run a 295/35/18 on the rear and 275/35/18 on the front with the Z06 wheels. Hopefully I will have some real updates soon for yall.

[Chevelle598bb]

After talking with Tobin about my brake set up I am going to ditch the power booster and switch to a manual set up. It will give me more room and clean up the engine compartment some.

[olblue51]

Hmmm... I think I've seen that car before

[Chevelle598bb]

Just a few times.

[Chevelle598bb]

Well I have been spending today trying to figure out how to get the rear lower on the car. When I replaced my 12 bolt with the Moser M9 rearend the rear of the car raised about an inch due to the bigger axle tubes and higher spring mount. I am trying to figure out if a set of circle track rear pigtail 5x11 springs will lower the car or not. My performance online drop springs are have about 9.5 inches of installed height. Im not sure if a set of 200 or 225 rear circle track springs will lower it. Also I was wondering if I could cut the circle track spring seeing as the first coil is unactive. That would allow a little more drop. Anyone got any ideas? You can see the difference in the rearends in the pictures above. The pictures of the car with the draglites on it was when I had the 12 bolt in the car. In post #5 the car has the Moser M9.