Im In the market for some headers, and i know that there are many differnt brands however, i currently have Aftermarket exhaust on my T/a, The pipe is 2.5" from the exhaust manifold back, Would it be worth it to upgrade to 3 inch?, because if i had headers with a 3" collecter, then it funneled down to a 2.5" it obviously would flow less once it hit the 2.5 pipe. And Seeing as a main point of getting header's is so the engine flows better, thats why my question arose. Thanks

 

search 2055 which is the number for hooker headers and you will find lots of opinions there and they will talk about other mfg's.
yes it will cause some restriction, but you can always get a reduction conversion from 3 to 2.5.
there is headman headers too. dyno don here on this board does a great set of headers.
good luck.

 

Sometimes less volume translates into more velocity which means better flow. You can have a system that's too big for the amount of exhaust your motor is putting out and it causes problems.

 

i know that dyno don runs true duals with 2.5 pipes but if you are going into a single pipe with a 5.7 3 inches will be perfect, any bigger will not.

 

Is there somewhere that tells me more about the actual physics of this ...why can too much space cause problems and what kind of probles as well ?... i have a 2.5 inc pipe noe muffler and im felling like it may be too free flowing.