whats the real difference?

What is the difference between a formula and a trans am besides weight. Any hp or trq difference?

No differences besides looks, and trans ams usually have more options.

I heard that the Formula was about 3-400 lbs lighter than the TA. but I have never weighed my car yet to know for sure.

Engine is exactly the same.

Formula is a Firebird with a V8 in it. Generally very lowly equipped, cheapest V8 you can get.

Trans Am is like the luxury edition, more expensive and has its own front/rear bumper, rear spoiler, usually came with leather, etc.

I doubt the difference is 300-400 lbs. Maybe more like 100lbs???