I just left Orlando last week. That was a good get away but didn't help me get my Z going!! I personally rebuilt the engine and the lifters. During the rebuild I installed a new oil pump but I will check the oil pressure at the rpm's you suggested to confirm adequate pressures. I am on my 7th oil and filter change with Casterol 10W-30 and Nissan filters since I am breaking the engine in. I only tried the LUCAS as a last effort snake oil to make the ticking go away. The first time I used Marvel Mystery Oil it made the biggest difference but the results are the same now. No ticking at warm up and loud tick after warming up.