Originally Posted by thinair
As a note, the 328 engine (M52B28) has a forged crank, stock. The hardest part so I've heard is keeping the head sealed to the block (blowing gaskets, head distortion, etc)
A lot of engines have forged cranks (i know the M50 doesn't), but that's not the problem... the problem lie's more with the stock cast pistons... they SUCK (for boost) on any car.
Especially with a higher compression ratio, you need to bring it down to at least 8.5:1 and be somewhat conservative on the timing if you want to make a stock motor last with boost.