Use the two piece neoprene seal. You will be much happier. The early 55 blocks had to use the rope, but all of the 57 235s I have built I used the neoprene. Btw, if you have to use a rope seal, try to beat the bushes and find an nos seal that is 20 or better years old. These should have the asbestos in the seal that allowed them to work. I agree with everyone else, the best gasket version is the best of the current stuff but you should really get an older seal for the best chance of success. Btw, I apparently do not possess the required skill to install a rope seal so the the motor does not leak, lol.
