Use the stock pump reconditioned with a remachined plate.
Mikes recomendations are there for a reason, and I'd follow it to the letter.
Make certain the pump filter is the new type, which are often anodised black. Reusing the old screen pickup is a bad policy unless it has been treated to a new screen. The distance from the face of the sump to the filter also should be more than 3/8". If its not, then the pump will be placing the cam under a lot of load, as oil creates a draw down curve which can put the oil system under extra pressure.
(1.The peak load on the cam when cold goes up when the volume goes up from stock.
2. On start up or at maximum revs, the bigger pumps cause spark scatter and extra loads on the cam and distributor.
3. You could reduce the oil pressure by using a thiner grade oil, or reduce the spring load, but the engine is likely to be clearanced and given rings of a certain type to suit a certain grade of oil).
