Rear Main Oil Seal

[cbostwick]

I need to change the rear main oil seal on a 1951 Plymouth Suburban which does not have the original engine. The current engine number is P24*33498* from a 52 or 53.
I was told this needed a neoprene seal not a rope seal and the crank shaft had to be dropped to replace it. It is almost easier to pull the engine he said.I am not a mechanic so any advise would be appreciated.