I have a 428 that I pulled from a '67 "Q" code stationwagon. It has a reversed "S" on the back of the block. I think the 428 blocks have "A", "C", "S" and maybe the fourth was an "I" or "P". I forget.
My block has all the heavy webbing like a 427 block. I could buy the 427 main caps and have mine crossbolted.
The suggestion to remove the pan and take pictures is a good one.
Dwight
