Will a 17X8 wheel with a 255/50/17 fit in the wheel well? I'm making a badass autocrossing project and basically need all the grip I can get on a 18 year olds menards profit. Also do any companies make tranny crossmembers for true dual exhaust, or will I have to farm it out to someone?

If youre going for autocross you should forget the 17's and probably go with 16's or even 15. 17's are too heavy to lug around on an autocross track.

should fit, thats what the impala wheels are, what year car

Impala wheels are 17X8.5" and very heavy. Autocross speeds are low enough though they may be a decent option. I use them on my car in summer and the extra grip is nice with the 255/50/17s.

im just saying that size wheel should work, not telling him to use that wheels, and i know there quite heavy

The cars a 84 with a freshly built 355 roller motor.