tregmatt....on a std ported head and BD10's you will struggle to get more than 1.5bar before surge city!..Saying this you may get 400bhp at that?????...and stick to greys 440bhp max..1000cc are good for 700bhp! Also if you only want 400bhp use the 4x4 ex manifold!

Chip @ 400bhp the std gearbox should be fine providing he dont launch it!