It would depend on the width and depth of the neoprene seal- - - - -it's not very likely that it would be a direct replacement for the rope seal, but at that price it's worth a try. If the seal can be made to fit the groove in the main bearing cap correctly, the same dimensions would apply to the block groove. If the groove is slightly too deep a piece of brass shim stock could be added to the bottom of the groove with heat resistant epoxy cement.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!