Mancini Racing rear main seal

I've installed a Mancini Racing rear main seal retainer on a 440 and will be rebuilding the engine. Does Mancini Racing sell replacement square rubber pieces? Has anyone tried installing o-ring pieces instead of the original square stock?

Thanks in advance.

I used o rings on mine found some round ones in and old gasket sets and cut the length I wanted out of them!

Did they seem to seal OK?

Yea and I still use silicone. a friend dropped over one day and said how in hell do you get those square in we said we don't we use these and he took my last stash of the o-ring of the right size! LOL dam he owes me.
Said it worked slick as too!!!
And he is a real mechanic!!

come to think of it we laid the o-rings in with silicone in the groves near the bottom and let harden overnight. then we trimed excess at bottom light smear of silicone everywhere installed and later trimed the oil pan side.