im not very good with cars lol but i think u need a swirl pot i dunno about anything else.......(reason i say this is cos i read in a magazine about a sapp 4x4 with 400bhp and i remember that bit lol!)

i also remember the person had an RS500 intercooler just like your getting and 0.63 exhaust housing, on i think a 2wd manifold.
wow ive impressed myself on what i remembered there is a bit more but i dont think it would be relevant to put down.

i was probably no help but still