Olds Rear Main Seal

[ronbz455]

I'm getting ready to pull the pan on the 307 Olds motor in the Regal and wanting to know what is the rubber rear main seal that you can use? Is JV748 for the Olds or the Chevy?

 

[olds307 and 403]

Felpro BS40612.

 

[ronbz455]

Do you have to shave the ends on this one or is it a correct fit? And what tips for installing it? I will probably check the mains so I can pull the crank down a little for clearance.

 

[ronbz455]

Also I wanted to up the oil pressure a bit so if I add some washers to the pump spring how thick would be enough and not to much?

 

[ronbz455]

Ok i'm changing the rear main on the 307 so I can drive it till I get the 403 built. I got the rear cap off and the bearing looks great! I found 2 choices. BS6141 and BS40612. The first one no trim. the second one you have to trim the edges because it has to flat sections on 1 half of the seal. I showed them to an OLds guy at work and he said the141 it's best to add a little sealer to the cap and block side and let them set up a bit. Then I showed him the 612 he miced it and said this is a little better. He didn't know about this one.

 

[Evan11]

Most use a Ford 292 rear main seal for their SBO as it's not the crappy rope seal. That's what I'd use.

 

[ronbz455]

When you used the Ford seal did you put any sealer on the back side of it? On mine the crank is still in it in the car so I guess a light skim coat would work.

 

[Evan11]

I would, yes