Rear Main Seal, why do you recommend rope seal?

These engines were originally manufactured with a rope seal. The rope seal has the advantages of being much wider than the rubber seal, they conform to irregularities in the casting of the block, and they absorb oil. If you want a leak-free rear main seal, we recommend using the rope. The only disadvantage to the rope seal is that you must have the crank shaft out of the engine to install it.

rope seal vs rubber seal