I heard they lightened the body on the 2.5 cars to get them down the road and that a V8 swap would twist the car apart (exaggerated I know) is this true at all?

 

Don't know C.M.All I have to offer is aside from the wt difference of the engines and different spring rate because the engine is that much lighter,I have never seen GM build a special car because it was a 2.5 or 2.8.I'm sure someone will chime in to help out.

 

On the assembly lines, the shells were welded up before any build sheet was attached. Every shell was made ready for any engine. Notice how the engine crossmember is already drilled for the V8 mounts.
Go ahead with a 383 or whatever you like, there's little point in a 2.5 to 2.8 swap.

 

Lotta maze for that swap, basically no cheeeeeze.

Bad plan.

There's no difference in the "frame" or anyting else, between a 4-cyl and a 350 one of these cars. Given that the 350 is about the cheeeeeeeeeeeeepest swap you can do ANYWAY, not alot of sense in doing anything else. Especially not putting some 6-cyl in your car which is CERTAIN to be a total disappointment in every way. If you're gonna do it, DO IT.

 

I'd atleast get some of those front crossmember brackets, I added those to my 84 v6. The holes for them are already punched.

 

No difference I could find in the cars when I had them.

I acquired an 85 yellow 4 cylinder bird with a perfect body, shelled it down, and rebuilt it with all the parts from a wrecked 86 T/A. All the body work and bracing looked the same inside with all the interior pulled out.

There were TONS of differences with the suspension parts, namely the Trans Am had stuff that wasn't on the 4 banger car, and the fuel lines were different.

If your 4 cylinder car body is nice, and you're looking to upgrade, All you need to do is find a wreck for a donor car. Z28 if you have a Camaro or Trans Am if you have a firebird. Shell out ALL the 4 cylinder crap, and reuse the Trans Am wiring harnesses too.

Have fun!!