It was very common to polish the seal area on GMC cranks. I suppose it was the same thing on Chev. I just can't imagine not being able to cut a rope seal. Are you guys doing it the way GMC recommends like I showed in a previous post? I have even installed a lot of them using a Sneaky Pete.

http://www.lislecorp.com/divisions/products/?product=134

After I packed them in with a drift punch, I cut them with a razor blade and that was that.