I use 5W20Wt on all the bearing ,pistons and rings, cylinders walls get lube off of the residual oil on the rings and piston skirts and I wipe the cylinder walls several times to get the excess oil off of the cylinder walls with a clean white rag to get them as clean as possible after thoroughly cleaning them before assembling the short block. No assembly lube for me, the motor runs on oil, correct
I use the cam lube call for by the cam maker on the lobes if it is flat tappet type cam and not a roller cam and lifter
you can not keep the motor to clean while prepping it and assembling it.
I do prime the motors and rotate them over on the engine stand with the spark plugs out and again before starting them in the car or on the engine dyno with the starter with the plugs out