M50 Head casting numbers

[surebimmer]

I bought two M50's to use for OBD I parts for an S52. I just took the heads off both M50's ones out of a 94 325i and the other 95 325is. The head casting number on my S52 is 1 738 400. The M50 out of the 95 325is also has the same casting number 1 738 400. I know the heads are the same on all US M5X/S5X, And the difference is the cams and valve springs. But the early head from the 94 325i has a casting number of 1 738 070. The head looks the same as the 400 casting. Anyone ran into this and are the head's interchangeable?

Thanks

[e30serg]

Make sure all the coolant holes are the same. That might be the difference.

[Jean]

Sorry I can't answer your question, but can you list the m50 and s52 Block casing numbers here for reference?

thanks!