I'm curious and can't really find any for sure answers as to what the difference in PARTS are in the US e36 engine which produces 240hp and the euro spec engine which creates 286/321Bhp? Obviously, the intake setup is different with a 3.5" MAF, 6 individual throttlebody's and what not. But is this the only thing that makes it different from the USA's version? Also I know the headers seem to be different too. But I can't find any other real difference's.