I am pretty sure if you put a 3 inch dp on there you will be surprised. That cam is pushing air and even if the dp is 2.5, then 3 cant hurt. Try it and i am going to guess at min. 5whp. So go 3 inch dp into a 3 inch highflow cat and tamper it down to 2.5. Just do it to cure my curiosity.

He will probably gain peak horsepower by doing that, but I also imagine he will lose low end power as well. Which depending on the type of driving he does might be a bad thing. I know the one thing I hate about my L36 is its lack of power below ~4k rpm.

3" is waaaaaaay too much for a 231CI v6 that'* N/A, in my humble opinion. Unless you're running nitrous, or some absolutely extreme build, 2.5" should be all you need. 3" if you're planning on turning 9k with a 230*@.050" cam with .650" lift, no intake runner to speak of, and heads that flow like the wind with a set of headers to top it off. You know that other high end parts would be required in that but that'* just a basic lineup.

i dunno on clubgp they are all running 3 inch on their GP gt'* and everyone is having great success. No loss in low end. Check out their L36 section.

Maybe it'* my line of thinking. Run a 3" down pipe, run 3" exhaust?

I dont know, i am not a gearhead but i know what i read and reviews. And everyone is having great success. I have heard of great gains and havent heard one bad comment yet. BUt now a full 3 inch exhaust i wouldn't request. Just go over their and start a topic. and get their adivce.

Everyone says it'* better but there is not one dyno to prove anything.

yes i guess you are right. Some one needs to try it out, and now their is a baseline dyno, after cam dyno, now do a 3 inch dp and do a dyno.

Well, It'* Ben'* car, and I do what he wants done to it. As it stands though, a 3" DP is out for him. Someone else will have to do it.