when bolting on an si head with the si intake manifold and ecu..........this is what makes it a cheap yet potent set up. not only does the headswap allow for better breathing but it raises the compression ratio as well. although the b6 pistons are only notched for an 8 valve head so proper cam timing is crucial to keeping from bending any valves. this also does not allow you to run an aftermarket cam.

 

Ah, missed the part about the head/IM/ecu. [8D]