"Big car" 455 frame pads, out of a '72 deuce-and-a-quarter if memory serves. They were blasted, and re-coated with POR-15. Part #'s - 1236486 and 1236487 $55 shipped in the lower 48.
Should be, they are the big car BCE frame pads. The two holes your motor mounts have are for where the bolt goes through them and the frame pads to hold them together.
Part numbers are 1236487 and 1236486 I believe, not sure if the last number is a 6 or 8. The motor mounts I have on my car have two holes on each side also, this allows for different mounting positions if desired. Do you have some pictures of your motor mounts? You can text them to me if you want at 262-844-0713.
Also, if you want to measure the distance between the mounting holes on the frame and let me know what those are, I can measure these pads to make sure they are the same.
Please let me know what address you're sending the parts to...I realized later that my info needed to be changed on PayPal