It's been a while since I've seen this done, but you'll probably want to swap the long blocks (block and heads) and use the manifolds and accessories for the Z in the Z. IIRC, there are a couple of sensors that have different connectors that take some work to make them work if you use the B-body sensor in the F-body.
I had a couple of friends who are quite knowledgeable in GM vehicles who swapped in a b-body engine into a 94-95 f-body. They mentioned the connectors, but I don't remember what they were. They also mentioned that their Z would run rough for approximately 30 seconds after a cold start. They swapped a bunch of stuff around, and borrowed my 95 Camaro FSM for a while to try to chase circuits and troubleshoot, but never discovered what the issue was. After that, the car ran fine, it was just a PITA to start and run in front of someone looking to buy the car after they put it together. They eventually sold the car like that, and AFAIK
, it's still running like that.
That issue may have been specific to that engine/car combination and have been fixed if/when they put the original engine back in the engine bay, but that was an issue they had. Since you're planning on doing so temporarily, you should have no issue with the swap, especially when you swap things back in.
I don't think you'll need a different oil pump. Just use the one that's already in the temp engine you're using.