Before I pull the motor back out to put another oil pump in I'm looking for some ideas. I went to break in my new rebuilt (by me) 454 yesterday and got only 6 psi oil pressure. It runs great with no noises, but as soon as I saw the oil pressure wasn't registering I shut it down. First thing I did was put a mechanical gauge on. Same thing. Next I pulled the dizzy and put a pump drive tool on and spun it with my electric drill for quite a while. Same thing. 6 psi max. I pulled the gauge adapters from the back of the block to verify there wasn't anything plugging them. Clear.
Even though I knew they were in, I went back through my pics and verified the gallery plugs are in. The only thing I modified was I drilled a small hole in one behind the timing chain for a little extra oil lubrication. I was thinking about pulling the remote oil filter off and putting a regular oil filter on to remove that from the equation.
Any other ideas?

what were your bearing clearances?sound like they could be off.also,that drilled hole looks awfully big.

I have read of people putting the lines to the remote filter on backwards and having no to low oil pressure. Just a suggestion to check the lines.

Bearing clearances were in spec. Mic'd them. No plastigauge used. Crank only had to be polished and was oe. The plug I drilled the hole in should be ok. I did the same thing on the motor for my 69 and I have plenty of oil pressure. I like the idea of the reversed lines, but they really can only go on the remote adapter one way if I remember right. Two different fittings. I think it's possible on the cooler, but I think that's free flowing right?

This is the one in my 69. It's also an L29 block.

did you braze or tig the pickup to the pump ?..........years back I had an engine installed and they did reverse the lines at the filter head, lifters rattled like crazy

Did the oil pressure relief valves get put back in ?

Against my better judgement I didn't braze the pick up. When I installed it I used the correct drive tool and it fit very/extremely tight. It wouldn't turn without some serious torque. I set the depth very carefully and installed the pan very carefully.
I'll move the oil filter from the remote housing to the block just to check the pressure and see if it makes a difference. I'll double check that I removed the center bypass and installed the other bypass at the same time. I remember doing it, but it'd be good to triple check.
I like the thoughts guys. I appreciate it. Please keep them coming.

I'm starting to think it might actually be a pinched remote filter line. It's a tight fit and hard to see down that side. When I still had the engine on the stand and spun the oil pump with the priming tool I got a big oily surprise where I didn't tighten one of the hoses on the filter adapter on the block. That tells me I had plenty of oil pressure at that time and nothing changed from then except me installing the FWC and installing the motor in the boat. I need to look closer before I start getting pissed at myself... I could see it getting pinched near the power steering pump/oil cooler.

Even with loose bearings etc you would get more than 6psi. It’s shocking how easy it is to reverse or kink the oil lines and that’s my best guess as well.