Knocking after installing new flywheel

[newshirt]

I don't see any evidence of scraping on the flywheel bolts or clutch pad. (see attached)

The ring gear looks to be up against the flywheel stop, and appears free of obstructions.

Do you think the flywheel bolts could be contacting the rear main (behind the flywheel flange)? I used the Snyder's flywheel mounting bolts and dowel retainer, as shown in the original post.