When I swapped a KE2x mounted engine into a KE70, I found that KE70 engine mounts were LONGER than KE2x mounts. So I would then
assume that the KE70 ones are the only different ones compared to everything else (meaning KE1x, KE2x, KE3x and KE55 are all the same).
I'm not 100% sure, but that's what my guess is.