So I ran my rebuilt 455 on a stand 3 years ago. All went well at the time. I am about to start it up again as it is now in the car. Is it necessary to pull the distributor and re-prime? At a minimum, I could crank it for 10-15 seconds without the coil attached and confirm pressure. Would that be acceptable? What would you do? Or am I overthinking this?

FYI. I am running a hydraulic roller....not a flat tappet.

 

I would pull the distributor and prime the oil pump. Might not be necessary, but why not take the extra time to get plenty of lubrication on the bearings.

 

Priming the pump with the distributor out is safest. If you don't want to do that, at least pull the plugs and spin the motor without compression load until oil pressure comes up.