this is a stock usdm itr header



this is the jdm itr header



with bigger cams you'll want to increase compression. the best way to do this is with new pistons. stick with oem pistons unless you want a bigger bore. p30 or jdm p73's work well. stay away from ctr's.

you must decide now whether you're going to turbo or not. you dont want to spend money on parts now that cant be used with a turbo setup later.

assuming the engine is healthy, you can easily make 250-300whp on a stock b18c1 and have it be reliable with good tuning and maintenance.