'89 roller-cam LA 360 w/Magnum heads - new roller lifters not pumping up

the lifters should pump up with a drill at 1100 rpm - that is equal to the engine running at 2200 rpm, and they are supposed to stay pumped up - unless they are fighting some killer stiff valve springs. I think heating the oil to make it thinner and pumping the plunger with a pushrod while spinning the pump will help get the weak lifters pumped up, and then they should stay up, if they don't replace them. I know the 8 brand new lifters did not flow much, but did they pump up and stay up? when assembled, is the lifter preload in the ballpark?