When I did the prelube on my new 235, I had to spin the makita cordless drill for about 30 seconds to get oil to the rockers. But after that, any rotation at all would bring the pressure up to 30 psi or so.
If you had the engine apart, make sure you installed the correct oil line or pipe plugs in the pushrod cover. 53-55 full pressure 235s used a small line, 55-62 235s had a 1/8" pipe plug blocking a passage in the center of the pushrod galley.
good luck
chip
