Exhaust size..2.5 into 2.25..is it really that bad?

[LatinEM2]

What do you guys think of this: getting a Profab header..and a carsound high flow cat welded into my Tanabe Hyper medallion.. they thing is that the tanabe is 60 mm..2.25 and the profab and cat will be 2.5 in.
Will i even benefit from that Profab header? i have a Comptech non-race one now..i do plan on adding cam's later on the road..(6-8) montsh or so..

 

[Jason-]

Just go and buy a 2.5 in cat. They aren't much more... Or just buy a test pipe.

-Jason

 

[MasterShake]

yea it'll bottle neck. not too much but it will.