flowmaster for my GP.

how much would a flowmaster kit increase my horsepower in my 95 grand prix?

what's in the kit?

exhaust parts?

smart @$$ lol....i don't know as much about the 95 gp's and what specifically is restrictive in their exaust that you can change. but genearlly if it's just mufflers i don't think you will see much performence wise, just the sound. if it includes larger pipes, high flow catalytic converter, or headers you could see significant improvement...