headers

[corolla_kid88]

how do you ports headers?

[winterbeater]

porting just means taking some sort of grinding tool and smoothing or reshaping headers manifolds and heads to match each others openings.
it can be as little as just removing or smoothing bad edges, or as extreme as changing the shape of the ports in the head. the idea is to have as effecient air flow as possible through manifolds, head and headers. if you dont have the proper tools, machine shops can do ti for you.