Truck Repair: Ford 460 Engine, oil pressure gauge, ford 460 engine

Question
Eric:

I have a 1984 Ford truck  with a 460 engine which I rebuit a couple of years ago.Has about 20,000 miles. A few days ago the oil pressure gauge dropped to zero. I gave it an oil change with new filter. Changed the oil sending unit. I replaced oil pump. Removed sending unit, checked pressure with engine running, showed very little oil getting to sending unit. Does not smoke or rattle. Any Idea whats going on?

Thanks a ton for any help.

George Meek  

Answer
I need more information to give you some direction --- When you rebuilt the motor - Did you overbore the cylinders and have the line checked?  Did you have the crank ground?  What did the rebuild include - main bearings - rod bearings - rings? What condition is the oil pan in?  Did the oil pan pickup get cleaned out?  -- What caused you to rebuild the engine in the first place? Did you replace the timing chain? --- they carry nylon coated gears in these engines and if the teeth break that can cause a sudden loss of oil pressure.

Thank you