Ok, I think I may have a problem.

Yesterday I decided to run this 468 hard and see if everything would hold together. After a few hard runs through the gears and about a 15 minute drive at 3600rpm at 65mph (its a jeep thing and low gears don't help) I experienced a problem. I exited the highway and came to a light, when I put the clutch in to wait on the light to go green I checked all my gauges. Oil pressure was holding at about 18psi, which I thought was odd. I continued to watch the pressure and it dropped to 0! Gave the gas a little tap and it came up to 40psi, then settled back to 22 psi for a second then dropped to 0 again! I used my hand throttle to set the idle to about 850 rpm which netted me about 22 psi and I limped it home.

It never gave me physical indications that it was low on oil pressure, no lifter taps or anything like that. So I pulled the electric sender out and hooked up my manual gauge to it and changed the oil to check for gas , water, or bearing material, none of which were there. I run 15w-40 Rotella-T and a 51060 Wix filter.

I let it sit overnight to make sure it was cool and got 50 psi at 620 rpm cold, and 60 psi at 1400 rpm cold.

After I let it get up to operating temperature I took it out and beat on it some more to get the oil nice and heat soaked, brought it back to the garage and got 14 psi at 630 rpm hot, 42 psi at 1400 rpm hot, and 50 psi at 2600 rpm hot. I could not get it to duplicate loosing all oil pressure, but this could be due to it being about 15 degrees cooler today then yesterday.

I installed a brand new Melling M-77HV oil pump when I put the motor together. I am a little concerned that I may have gotten a bad pump. Does this sound about right? I was thinking about buying a Milodon pump to have on hand when I drop the pan to inspect the bottom end for damage.

I can not find my sheet with all my clearances written down, but if it were bearings I would expect to see less pressure being made when its revved. Or am I mistaken?
Thanks,
Clay