One more things to remember besides bleeding the lifters correctly and choosing a good headgasket. Remember to check the if the new oil pump is flushed with the block. If not flush, machine down the oil pump. If flush, remember to apply nissan gasket maker in the front where the headgasket meets the oil pump and head. Apply to both sides.
For headgasket, buy APEXI period. Apexi uses a Full Grommet style, which means that the cylinder sealing is a full ring that encapsulates all three layers. This is the best possible protection for your engine.
Keep this in mind when buying Apexi headgaskets, 86mm means 87mm and 87mm means 88mm, etc. When you by 86 x 1.1mm, you'll get a 8711 (87x1.1) on the headgasket. The reason is that when you buy head gaskets, its bore size should be 1-2mm bigger than your cylinder bore.