i have a similar question, i have an RB20, with full 3inch turbo back exhaust, FMIC, Fuel pump, ECU running on MAP sensor (no AFM).
i have been offered a stainless steel mainfold and brand new ( he has receipt) T04E/T3 with .67 AR.
how would this go on my motor? or should i just grab the mainfold and get a RB25 turbo too?