I just got a 92 Camaro its got the 3.1 V6 in it. But its been bored .40 over. Is there any horsepower gain since they did that? Also i am looking for sugestions for the best exhuast to put on this thing. I need to put on a new CAT and back. The car sat for about 9 years.... and hasnt ran in about 2 yrs. I am getting to the cleaning and the tinkering slowly... Any suggestions would be great....

well my suggestion is take your loss on the bore job or sell it, and go find yourself a v8, you can find any part for a 305 or 350 thats performance, and there easier in my oppinion, but its your car. i had a 3.1 in my 86, and right off the bat i just knew a 350 was gonna go there. but thats up to you, boring out a 3.1 tho, i dont think ive heard of that before.....
as long as theres no other problems with the motor, then ya, it should make some difference, and upgrade some other parts, you can do some computer tuning, injectors, throttle body, air intake, exaust (custom?), head work, cam if avail. your problem will be finding all theese parts, for sbc, there easy to find, but 3.1 may be harder to find.