Thanks for the reply. I'll try your suggestion. Here's some photo of what I'm working with.
The old seal:

The new seal:

The wear area:

That shiny grove at the right of the photo is what I'm worried about. In some areas it's not very deep
but in some you can feel it with your finger. I don't want the put the new seal on and still have a leak.
You're right about that seal, wasn't cheap for sure.

I was also thinking about cutting the seal out with a Dremel but I don't want to cut into anything behind the seal accidently.
58 Ford Custom 300 - San Pedro, CA (So-Cal)