[lukecp]

The last 3 digits of the casting #'s will be:
461, 462, 492, 041, 186, and i believe 291 was also a casting number. The 492 and 186 heads are pretty desirable b/c they have accessoy holes for alternator and A/C brakets, while the others do not.

And yes, camel hump heads aren't the best hi-performance heads out there, but i love mine. You can still use all the standard intakes, valvecovers, and pushrods for any SBC, and getting a rebuilt pair with a little porting work done is still a couple hundred dollars cheaper than a pair of Dart or World Products heads.