A 62 motor should be machined for the neoprene seal. After you have confirmed that the bearings are not causing the binding problem, get a neoprene seal and install that. They are getting a little hard to come by these days but see if you can find one. The early 55 and prior motors were not machined for a neoprene seal and if you install one, they will physically fit but will sink deeper into the block and cap so will leak. So you cant use a neoprene on the earlier motors. The later motors, starting in 56 for the passenger cars, and I am assuming for the trucks also but you never know, were machined for the better neoprene seal. I actually don't know the answer to this question but I don't know weather you can install a rope seal into a rear main cap that is machined for the neoprene seal. My gut tells me yes but I really have never looked at that issue because I avoid those rope seals like the plague.
The other thing about the rope seals that are supplied today is that they are not like the seal of old. The original seals contained asbestos and the new seals contain fiberglass. The older seals worked better. So if you have to use a rope seal, or you insist on using a rope seal, see if you can find one that is 20 years or older.
Best or Felpro Neoprene is 4519S, CR, McCord, Victor, and others also made them.
If you have a neoprene seal that is leaking, try using the Barr's rear main seal leak stop. It is not like the pellets from years ago for the radiator leak stop. It is a clear liquid that goes in with the oil and swells the seal. I had the neoprene seal on my 261 leak almost from breakin. Used that stuff and it stopped the leaking.
Last edited by Dragsix; 01/26/2018 4:32 PM.
