This may not help but a long time ago i herd the flowmasters restricted more airflow than some of the others on the market. It was from an exhaust shop owner. and it may have just been his opinion
Well, they dont flow super-duper great like a spintech or an open muffler like a pro bullet but they do flow good enough! I think the best one they have on the market right now is the SUPER 44. It is supposed to out flow all of the other flowmaster mufflers....I think. One of the muffler shops in town really hates flowmasters & he will say anything about them in order for you to get magnaflows. He has even gone as far as telling the kids that flowmasters are bad for your valves. What a crock!!
