'71 Pontiac Firebird Build

[ccm399]

Hi all,

Kinda new around here (by post count anyway) but I wanted to start a thread for my project. As the title indicates, I have a 1971 shell I found over in St Louis it needs a bunch of work but the price was right... Plus the quarters are solid.

Anyway the plans are:

LS engine probably a mild Twin Turbo 6.0 but I am toying with the idea of a hybrid smaller CID LS engine, still twin turbo though. :)

Corvette driveline including 6l80e trans. I know, I know, those transmissions ends are not known to be the strongest but there are guys working on them so hopefully by the time my car is ready for the street they will have the kinks worked out.

Corvette based suspension on all four corners. Possibly on Ridetech air bags, not sure yet. I will be fabricating a full custom chassis for the car.

Mild body mods.

Custom body and trim colors (No chrome).

Full custom interior, no rear seats (Think Scar-ish).

Baer or Willwood big brakes. 6p up front 4p out back.

275 35 zr18 up front
335 30 zr18 out back

Forgeline (most likely) S03 centers powder coated to match trim and hoops brushed and clear powder coated. Well, that is the plan as of now anyway, we'll see what they have out when it comes time to buy wheels!

This is going to be a long slow process so bear with me. Time and money are both a little tight right now but by mid summer we should have my wife's car paid off so that will free up some capital! I hope to be able to start on the Chassis by October or November of this year.

I can't post pictures from here but I will get some up ASAP.

Thanks for looking,

Chris

[T_Raven]

Sounds like a heck of a plan, can't wait to see pics

[tazzz25906112]

Should be a killer project Chris,,, welcome aboard and let me know if I can help with any Carbon parts you may want in the build.....

[ccm399]

Thanks guys,

Here are a couple pics from the first day we got her home.

https://static1.pt-content.com/images/pt/2011/02/DSC_0395-1.jpg

https://static1.pt-content.com/images/pt/2011/02/DSC_0400-1.jpg

https://static1.pt-content.com/images/pt/2011/02/DSC_0401-1.jpg

I've got her all stripped down other than suspension, doors and deck lid now though.

[ccm399]

I have also been toying with the idea about putting a Pontiac engine in her. I know the Pontiac purists would like that. I don't care either way, my '89 Trans Am drag car had a SBC in it... We'll see when we get closer to that part of the build.

I see Butler Performance offer an aluminum block for the Poncho crowd so that makes things interesting.... but at almost $5000 that hurts a bit... Even their aftermarket iron block is a decent chunk of change. I think if I was going to spend that kind of money on a block I would go all out and get the aluminum one.

[aronhk_md]

Hey Chris.....welcome :)

The 6L80 isnt a weak trans......but unlike the 4L80 it needs to stay with its engine combo apparently so you can use its original computer system. That said the 4L80 can be had with aftermarket computers, and is now available several places as a 6 speed. I know they can be built to handle 1500 hp. When you get a chance post some pics of whatever you are doing with that NOSE..........lol

[ccm399]

Hey Aron,

Interesting, from the reading I have been doing the 6l80e has an internal TCU and only needs a few inputs to function "correctly". Of course correctly would be the way GM wants it to maybe not the way I want it to. I am worried that even with tuning it is not going to shift like the ATI 'glide I had in my Trans Am....

[aronhk_md]

I thought I had read otherwise.....lol. But theres tons of info on these transmissions here in the automatic transmission section.......and the people who build them post here too. But from my understanding the 4L80 can be made to shift any way you want it to with computer maps you develop yourself. So if you want one map for cruising long distance with early lockups and soft shifts across the board, but another map for racing with neck snapping shifts.......or a combo of both depending on what your throttle position indicator senses.....you can do it.

[dlrepmn]

Go with your original plan. Got a buddy (from Pro-Touring.com) who paid huge ching for Butler with major HP in a ragtop and now he is trying to keep it from overheating. He will work it out, but is stressed out after paying big cash and working really hard on a very, very nice car.

Damn sweet idea. Build it the way you want it.

[LeighP]

From one 71 Firebird builder to another....congratulations on picking the best car for your project! :)

[ccm399]

Go with your original plan. Got a buddy (from Pro-Touring.com) who paid huge ching for Butler with major HP in a ragtop and now he is trying to keep it from overheating. He will work it out, but is stressed out after paying big cash and working really hard on a very, very nice car.

Damn sweet idea. Build it the way you want it.

Thanks for that. While the block's description says fully water jacketed that does not mean won't overheat. Either way I will be buying parts and doing all the machine work, porting and assembly myself. I was an automotive machinist for 15 years before changing careers...wishing I hadn't changed except for every other Friday...

[ccm399]

From one 71 Firebird builder to another....congratulations on picking the best car for your project! :)

Agreed! :)

[ccm399]

I thought I had read otherwise.....lol. But theres tons of info on these transmissions here in the automatic transmission section.......and the people who build them post here too. But from my understanding the 4L80 can be made to shift any way you want it to with computer maps you develop yourself. So if you want one map for cruising long distance with early lockups and soft shifts across the board, but another map for racing with neck snapping shifts.......or a combo of both depending on what your throttle position indicator senses.....you can do it.

Who knows maybe I misunderstood... I'll find out for sure soon though!