RJC Biggie requires a 1" socket to install. 26 mm will work, too.
The GM torque spec is 30 lb-ft.
Might be a good idea to replace, or have on-hand, the o-ring that seals the rear of the cooler adapter to the oil pump cover. The o-ring is GM # 25530999.
It's a relatively easy job, considering that very little on TR's is "easy" !