Do all old trucks leak or is there an acceptable amount?

[67 twins]

Originally Posted by HO455

Rear main seals can be a problem on pre-Vortex engines as the original rope seals had asbestos in them and we all know that's verboten these days. If you need to replace one the best ones are made by Best Gasket, their grafite rope seals.

That being said poorly fitting oil pans contribute to many suspected rear main seal leaks.

Replacement of the rear main seal can be done without removing the engine but you will need to loosen all of the main caps to drop the crankshaft down so you can get ALL of the old seal removed and get the new seal properly seated and cut to size once seated. There's folks who say you can pull the new seal in with the old seal by tieing them together with fishing line but I've never made that work. Personally I would rather pull the engine to replace the main seal. It also makes checking the oil pan fitment easier.

Wait! What? BBC use a rope seal? I thought they use a 2 piece rubber seal same as SBC. Tell me I'm wrong & I'll shut up. I've never had a big block.