First time with aluminum heads:

make sure you subtract at least a few thousandths from your recommended lash spec for growth. I didn’t subtract enough and had a pushrod kick out once my 451 warmed up for the first time.

Tape the seats before you get after the bowls with the grinder. Tape won’t stop a burr, but it may save your bacon in the case of a split second “ooops”.

I would NOT use shim style gaskets at the headers or anywhere else on aluminum.

As long as you’re where you’re at:

Before you install the heads, check PtoV clearance for future upgrade potential.

CC the chambers to be certain your compression is where you want it.