Doug's headers not fitting - frustration

I may end up with a truck biscuit too because it seems like no matter what I try the mounts just go all the way to the bottom of the slot on both sides.

Do I just need a mount for a late 70s D-something with a 360?
Like 1985 d 150 v-8. Anchor 2469 is a part number or pioneer 602469. Both available from rock auto for dirt cheap.

I had to drill the metal bracket a little to accept the stud on the new mount for a proper fitment. Easy peasy