Will soon be ready to drop the crank back into my block. Been gathering parts for the rebuild for some time, and have a Fel Pro rope seal for the rear main seal. After reading a lot on this and other forums, TA website, etc. it seem like something other than rope is recommended, but I see information on Ford seals, and Cadillac seals. My engine had a rope seal when it was taken apart, and it was not leaking. Are replacement rope seals that bad? I have owned Fords with rear main leaks, but not a problem with any GM products. This is a 1970 455. Have read Jim's detailed installation from Tri-Shield, but I don't see what part he is using. Thanks for any recommendations.
I read that the newer rope seals do not have the graphite or lead in them like the originals or older replacements did.
This information is very timely for me. Thank you for this post. The rear main seal on my 425 Nailhead is the only thing leaking on the engine. I was looking at a rope seal, thinking that since they used them new, this must be the way to go. Then I read this post . Okay, a rope seal is out, unles I stumble across a NOS one. I will look at the rubber ones. This is not something where I will go cheap. It has to last for years, so, get the best.
I have a buddy that builds Pontiac's that swears by these rope seals. https://bestgasket.com/rear-main-seals/#buick
Rope seals were ALWAYS a pain in the ass to install. They're still popular in the Pontiac world, because some Pontiac blocks don't have the seal groove machining concentric with the bearing saddle. A lip seal may be crushed in one area, and not touching the journal on the opposite side. I haven't heard that that is a problem with Buicks. Aside from being better-able to deal with concentricity issues, rope seals handle abrasives better than lip seals. If you've got abrasives going through your oil system, the rear seal is the least of your problems.
Chuck I have those seals, rubber, in stock for about 20 years now & send directions on how to install them that no one else has & how to do them in the car. Tom T.
My financier (the wife) says yes, add it to the pile. I do not need it right away as I am not in a position to change it until the fall anyway. Thank you Tom.
