ok well maybe this will go over better in this forum.....

ok well i have a b18a1 motor i'm puting together for my dd. and i'm eather looking at using my cast ls manifold or build a header. now i'm more then capable of fabricating and welding a tubular header together.
my main question is i have no clue the breathing needs of my motor and the last thing i need is to make a header that is to big, small etc...

now i'm not aking for build plans so to speak ( not that i would expect that or want that). but i'm more looking for a good start to work off of.

specs:
81mm b18a1 w/ pr3 pistons, (11.4:1)< zeal auto comp. calculator, stock head/cams, modded gsr intake manifold/t body, stock gsr intake, and a 2.5" header back exhaust.

only thing i will be getting in the future will be a set of crower 404's and valvetrain.

ok guys lmk what you think

now i know i won't be mastering building n/a header's over night but what the hell i thought i would give it a try....

 

anyone???