I am looking to turbocharge my M44 motor and want to build the bottom end for a lot of boost so am going to fit forged rods and pistons. In order to finish off the bottom end I was wondering if the crank out of a M42 engine would be a straight swap into a M44 block. As the M42 crank is a forged item I thought it would be a cheaper way to a full steel bottom end. In addition does the M42 get it's smaller capacity than an M44 from it's bore or it's stroke? If it's the stroke it may solve my 'how am I going to lower the compression' dilemma.
Any help would be much appreciated.