most probably know this but for those who don't here's how.

Early V-8 used 'nickel dispersion-coated' cylinder walls and according to BMW, the high sulfur content of some [many] fuels damaged this coating leading to sealing and [in some cases] complete compression loss. A new block composition of 'aluminum silicon alloy' has eliminated this problem and early [as little as 2,500 miles] failure of the cylinders though a number of the replacement short blocks installed were of remaining stock of 'Nikasil'. 'Alusil' is used on all M60, 62, 70, & 73's.

The casting number is on the right side of the block just ahead of the starter motor. [it's cast not a stamped in number]

casting number block version
1 725 970 or 1 741 212 M60 B30 Nikasil
1 745 871 M60 B30 Alusil
1 725 963 or 1 742 998 M60 B40 Nikasil
1 745 872 M60 B40 Alusil
1 745 873 M62 B44 Alusil

hope this is use to some of you............................................... ...jb.