I figured if I’m taking it off, might as well replace it. I also want to replace the oil cooler lines. Not sure where the leak is coming from.
Replacing the adapter would be a strange thing to do. It's not a wear part. Just replace the gasket. If it's like the adapter on the 454 it's just a big o-ring that can be gotten from the dealer. The small block adapter uses a paper gasket too.... not sure if that's available from the dealer. I think guys often by a Felpro kit.
The lines often leak... don't buy Dorman as they'll leak in a year or two. I removed mine completely after getting tired of leaking lines. I've considered buying Sunsong lines as they're supposed to be steel like the originals, instead of the aluminum that Dorman uses. AC Delco are available too, at least for my truck, but they're a lot more expensive.
You may have quick connects on the lines... probably ought to replace those, too.