MyE28.com

I got a m30b32 I'm swapping in a e 30 it's out of a 1983 533i got everything out of the donor car. And took the valve cover off and looks pretty good so far other then the timing chaing is pretty lose gonna drop the oil pan soon just have been busy possibly thinking about fully rebuilding it and preparing it for boost. I've been looking around and from what I've read it's pretty easy on these but the b32 heads have shity flow. Can I use the b35 head and head gasket ? Can I bore the b32 block and use the b35 low compression pistons ? I believe the b35 bore is .03 bigger and the strokes the same ?

That doesn't really answer my question

I think you're better asking in the normal tech section.
You're asking about bolting together different variants of the m30 to see what works.

I'm going to say you can.

Cost wise your better off using the stock b32 then when that motor fails getting a complete b35. There's someone here that has been beating the piss out of a b32 and it's still running strong.

mitch is right.
boost the b32 as is till it blows then get a b35 or b34bottom/b35top.