ok switching from tti step headers to 1 7/8 race header, motor made 583 hp with the steps , has anyone tested or dynoed the race headers with 3 inch x pipe and muffler against 3.5 x pipe and muffler to see which is the best or anything similar?
I remember reading an article that was testing a SB stroker motor. It made fairly significant more power with the headers that had 3.5" collectors over the 3" collectors. I don't recall the numbers but it seems like Shady Dell maybe did the testing and write-up on it.
i believe you are thinking about the article with IMM´s 620hp build
http://www.hotrod.com/how-to/engine/ccrp-1110-pump-gas-small-block-mopar/
I am getting more and more excited about those headers, wonder if anyone has done any testing with 3 and 3.5 exhaust after the collector?