1 Peice rear main seal

[ou812545]

I recently had my 418w rebuilt. It's a 1971 block with the 1 piece seal.
The problem we ran into is the block was aligned bored a few times in it's life and the 1 piece seal did not want to stay in place. Due to the machine work, the location of the seal is no longer a perfect circle. The seal would actually work it's way out overnight as the engines sat on the engine stand. We tried some permanent cement and it seemed to work, Until!
We installed the engine over the weekend and after the first 100 miles, the seal is now leaking. We suspect it's coming from the out diameter. Between the seal and the block and bearing cap. No the seal and crank. We used the rigged steal stamped Fel-Pro rear main seal.

My question is?
Is there a rear main seal you recommend other than the Fel-Pro that may work better when the block has been align-bored a few times?

I can't be the first person to run across this problem.. Any suggestions?

Thanks,
Dan