Ok here's my question. What is the most powerfull engine I can slap in my 1987 Trans-AM and not need to use a roll cage or make any major structual changes. I would be willing of course to strengthen the vehicle. But not at the expense of my interior or functionality. Emissions is also a factor. I would still like to drive the car on the weekends. Maybe a little track use. I am planning on saving up for awhile and theres alot of powerfull engines out there. I just want an idea of what I need as kind of a target or direction for my savings.

 

Since emissions is a factor, assume staying with a small block and TPI.

The only "technically legal" engine is a 350 with normal rebuild over-bore. But, since a 350 SBC looks identical to a 427 SBC externally, and you don't have to go through polygraph when you do the emissions thing, you could go nuts with the displacement and figure out some way to feed it with TPI.

But, more down to earth, figure first on subframe connectors and poly bushings all around if you haven't done so already. With any kind of power, figure on beefing up the rear end (either 9-bolt or 10-bolt), check out the tranny and drivetrain forum for more info along that line. Then, the TH700 would benefit from some aftermarket aide, same forum. You'll need to get the power you're going to make down to the ground, so figure on boxing your lower control arms (or go tubular), and LCA relocation brackets are also a very good idea. A roll cage can be done without major sacrifice of daily functionality, but it starts complicating things, for sure.

Back to the engine: A 383 or 406 TPI isn't all that out-of-bounds. Figure on upgrades to the TB, runners, and at least porting the base if not upgrading with an aftermarket piece (like Big Mouth), and porting the plenum. Then, you're looking at adjustable fuel pressure regulator, bigger injectors, and a good measure of PROM tuning (figure on getting the burning equipment up front, avoid the custom chip expense since you'll probably end up reprograming for yourself, anyway). Keep the cam reasonable (ZZ9 or some other computer-compatible grind). The TPI forum is the place for more detailed info on all that.

Exhaust is a foregone conclusion (headers, high-flow y-pipe and on back). All available in emissions-legal form.

"Power is in the heads", so don't skimp there - AFR is the logo that typically gets the "can't do better" nod.

Should be able to cover all that for $10-12k. You didn't say money was a factor, after all...

 

Yeah what he said.

Also to further add, don't skimp in the chassis department. My stock 92 would flex if I tried to launch hard or enter turns fast. I do have T-tops so that may not be an issue for you. However with the added torque (read: gobs of it) of a healthy 383 or 400, you can twist your floorboards out. Not literally I hope but you get the idea. I did see the floorboards twist and crack, in a Fox body mustang though.

I made my own subframe connectors out of 2x2 mild steel square tubing. I ran them along the rocker panel from the torque box area up to the lower firewall. It grabs onto the front and rear "subframes" as well. Basically my car now has a full frame. I also built a six point cage which made my back seat very unaccessible but did not interfere with the front ingress egress very much. My list of chassis mods continues but you get the idea. A solid chassis goes a long way in overall vehicle dynamics and attitude. Not to mention making the driving experience more fun.