http://6066gmcclub.com/attachment.ph...5&d=1456445855
^^^^
Here's an attachment showing what looks to be all casting numbers of heads, blocks, & crank forging #'s. beerman posted that on a thread a few months ago, o e of his first posts on this forum (thank you!)
Here's the info relevant to my quest for a 351E/M or maybe a 401M, or else a Magnum top end (from a 432 or 478M) for my 305D:
All 351E, 351M, 401M, 432, & 478M came with Magnum heads, casting numbers are:
*696032
*2421158
351E & 351M 1966-1973 block #'s
*2476578
*695318
401M 1966-1973 block #'s:
*2457329
*2476579
478M & 432 engines will still have the same Magnum head casting #'s but will be much more industrial/commercial application engines, 8 bolt crank vs 6, not a passenger truck engine
_________________________________________
If it's not a magnum engine, here are the #'s:
351C blocks:
-2378091
401 60-66 blocks:
-2457329
-2476579
351C & 401 heads:
-2436646
-2436647
-2366811 (351C only)