right so far I've got a set of dark green injectors,my mate has a cheap st170 engine (I'm hearing its best too use these as they have forged internals but even still do the internals need too be changed)? what head do i use (st170 head or blacktop head)? what headgasket? and do I need decomp plate? what inlet ,turbo combination do I use (is a frs one any good)? cheers Wes