Oil Pump change on 1993 G20 350CI

I need to chane the oil pump on my van and I was wondering if anyone has had experience with this. My manual says I must raise the engine 3 inches, is this the case? The parts store says I should change the oil pump, pickup and distritutor shaft. Is all that really recommended?

Any thoughts would be appreciated.

3 in + is better. Pump and pick-up for sure. Shaft if the end looks bad.