Some years ago I had a GMC 270 crank out of a CCKW ground -.030/-.030 and stored it until just recently. While getting ready to install it I noticed the rear seal surface is a little pitted. I set it up in my lathe intending to grind the seal surface. (using tool post grinder) I put an indicator on the flywheel flange and the seal surface and got about .001" run-out...looked good. Then I checked the rear main bearing and got about .004" run-out.
My question is...is that too much? Looks like that won't help the rope seal any. The shop that ground it is out of business so no help there.

I could:
1) Dial in the rear main bearing and grind the seal surface to match. I would think the rope seal would be pretty forgiving on size, but this would leave the flywheel running out the .004"
2) Have the whole crank reground to -.040 (expensive option)
3) Do nothing and just put it together.

Has there ever been a rubber seal conversion for the 270?