Pontiac 455 rear main seal

[BA.]

Was hoping to tap into the knowledge of the Pontiac enthusiasts here.

I've got a buddy with a pretty strong 455 in a 67 GTO that he drag races.
It looks like his rear main seal is leaking again and I thought i had read something in a magazine in the past about a good fix for Pontiac big-blocks with this problem.


Anyone have any special tips?

[67gtonut]

http://www.bopengineering.com/beltdrive_acc_topend2.shtml

Viton Rear Main Seal

or the new Graphite Rope Seal

http://www.bopengineering.com/pontiac_replacement_parts3.shtml

Either way..... motor has to be pulled ....

[critter]

True. I have the BOP seal but that was because they were the only option at that time. The graphtite seals are getting great reviews. A few folks have had issues with the BOP seal due to inconsistent machining of the original seal groove in the block and matching main cap. YMMV.

[hectore3]

The Graphite stuff is the way to go. And just so that you know for the future Pontiac never made a big or small block. All Pontiac blocks besides the odd ball 301 turbo look the same externally. Displacement was made through bore and stroke changes.

[BA.]

Thanks guys - sounds like the cheaper Graphtite seal will work just fine, although we'd spend the money for the other one if it was worth it.

Here's the ride it's going in. Engine is now out and ready for it's new seal!

https://www.pro-touring.com/forum/attachment.php?attachmentid=41479&d=1287329756

[wmhjr]

Use either the BOP engineering viton seal, or the graphite seal from Ace at PP (http://www.pacificperformanceracing.com/products/gaskets.html) . You'll need the 3.25" size for the 455. If installed properly either should work. I personally like the BOP seal better but that's just me.