The offset oil adapter does not have provision for the cooler.
The right side cat won't fit because the frame is not notched out like on the LT1 cars. In fact, the whole forward frame on the LT1 cars is a little different.

If you are running aftermarket cats and the diameter is smaller than OEM, they will clear. I can give you the exact specs as I cut and rewelded an OEM cat to fit.

You will need to run LT1 shorty headers as the stud spacing is wider on the LT1.

Mine leaked like nothing else for some reason. I took it all apart. My headers are not "perfect", but I think the used cats I bought - I think the socket flanges on them are warped. If you made them together on the bench there is some gaps where it was leaking. I got pissed off and won't be putting it back together this way.

The offset oil filter adapter is cool though. even if I go another route, it will keep the oil filter a bit farther away from the exhaust.