The motor has probobly 150000 miles on it. It has a cold air intake, aem adjustable cam gears, apexi exhuast, stage 1 cam, stage 1 clutch and gsr 123 gears. The motor and rev up preety high with ease with my cheap ebay 4-1 header, but I want to upgrade to a little better exhuast performance wise. Would the DC 4-2-1 header be good since it adds some low end power, or if i get that i will lose lots of high end effencieny? Please help.

 

A 4-2-1 will give you a little better mid-range over a 4-1. Match it with a hi flow cat and you may notice a little bump with a butt dyno.

 

unless you have to deal with cali SMOG, the DC is just a jdm itr replica get a hytech/toda rep from PLM. i'd highly recommend the TODA rep from them.