Hello,

I'm replacing the rear main seal in my '57 235 six cylinder. It was rebuilt not too long ago, but the rear main seal leaks. When I took off the rear cap I found that part of a shim was over the top of the rear main seal, between the two pieces. It appears to be a thin copper shim. Do I need to trim this off for the two pieces of rear main seal to seal properly?
I've never seen this issue before.

http://i156.photobucket.com/albums/t24/vetteman61/IMG_1418.jpg

Thanks,
Brandon