Built e30 m20 b25 from e34 m20 b20 engine block

[markus_74]

Hello, Zoner

I have difficult to find any e30 m20 b25 high compression here, so I think I will built it from e34 m20 b20 engine block (1989).

Does is it possible? and what difficulty?

I have read wiki zone that it will difficult because :

1.oil check dipstick will be different location

2.engine block not match with b25 cylinder head this is wiki said

"The heads themselves are not interchangeable; fitting a 731 head to a 325i will result in the valves hitting the pistons, while fitting an 885 head to a 320i will result in the valves hitting the bore lip. 885 heads are therefore completely incompatible with B20 or B23 blocks"

so what head should I use and what the sign and from what year?

Thank you need all advice from zoner.

Thank you