Originally Posted by kellymoe
ERR4936 is the one i think I have on there now but not 100% sure. Both fit the same on the block. I'll know for sure soon.
ERR7280 on the left & ERR4936 on the right but flipped over.
If you look at the attached pic the early cam driven pump cover is on the left & later crank on the right. The hole in the casting circled in red isn't fully covered if the later gasket (ERR7280) is used. The earlier type gasket can be with or without a hole, doesn't matter as there is no corresponding hole in the block but the cover hole needs to be sealed. That's why some pattern gaskets don't have that 3rd hole on that side.... prob makes then a bit cheaper as one less cutter on the die punch (eg the one in the Craddocks pic)
Corresponding location (with no hole) on the block circled for reference.
Hope that makes sence