This is a hypothetical situation. Let's suppose I go out and buy a 400hp 350. Let's say it is fully capable of making 400 hp with headers and open exhaust. Now, how much hp could I make if I put on stock exhaust manifolds from a 305 and have a 2 1/2 inch exhaust? What kinds of problems would this cause? I'm new to the car technical stuff, and I was wondering if some of you tech gurus could answer this.

 

all you would be doing is choking it off. going by the info given i'd guess about 45 to 55 hp cut down from the rating. basicly at low rpm the difference would be there, but not nearly as bad as upper rpm. it would feel like your not into it all the way. also hard on the rings and can cause it to run hot easier.