3" exhaust? 2.5" exhaust...??

ScampMike said
your statement is way too broad - not all small blocks are created equally - nor are all big blocks... MOST mid-level performance engines will do well with a 2.5" system - big or small block.. but once you get into the higher HP ranges (I think someone aptly stated above 450HP) a 2.5" system could be restrictive - again, big or small block. I would venture a step further - if you are approaching 400HP - a 3" system will likely work well for you.

stroked340 said
Maybe on a stock or lightly modified small block it is,but you start stroking them and making real power I'll take my 3" system any day..

I don't find the statement to broad. I see it as accurate and very much so to a degree.
I guess this truth depends on the end users use of the car followed by the ears abilty to put up woth the noise. I don't consider his build particularly powerful. I'm sure he is making a bunch of it (HP & TQ) and it is a barrel of fun for sure. The engine masters exhaust tube video is an interesting one. it was a 15.7/13 TQ/HP gain on that engine. Of course, your results may vary.....
620hp/580 - TQ open header
614/569 HP/TQ - 3 inch exhaust
601/554 HP/TQ - 2-1/2 exchaust

I like Steve B's exhaust sound mention at 6:52 into the video. A lot of truth there.