Ok, I guess we aren't the sharpest toll in the shed. We lost oil pressure! Information you need is this is a '72 true 390. We measured the stroke. Motor is probably a reman, however the truck itself has only 64K which I have all the documented paper from the original owner. We changed the intake manifold to an Edelbrock performer and carburator, replaced the old distributor with a new HEI, new water pump and mechanical fuel pump. New plug wires and everything bolted up to fire the motor. Before starting the motor, we pulled the oil sending unit and cranked to make sure the Dizzy was in place. Oil squirted out, and that was a good thing.
So now we fire the motor which started right up, and we have no oil pressure. Checked the in cab, as well as put a mechanical on this. Both show nothing. The truck was a daily driver and drove it into the stall before the upgrades. So please, anyone with any thoughts let us know.

 

Pull the distributor out and inspect the oil pump driveshaft. Get a 1/4 drive socket on an extension and spin the oil pump driveshaft counter-clockwise with a drill and see if you get oil pressure.

 

also to be sure the pump shaft didn't fall into the pan

 

Pull the dizzy out again and it should just clunk when you drop it in so you know the shaft is all the way. This HEI just doesn't do that so we tried again and now with the mechanical we show good pressure. I still don't trust it though. I will keep an eye on it

 

Isn't that one of the most sickening sounds you ever heard when pulling a dist and you hear the pump shaft fall. Been a long time though.

 

Maybe check the HEI that it has the 1/4 hex shaft and not damaged or stripped. And may be since it made off "SHORE" all kinds of things can get shipped to the US.
orich

 

After pulling it out a few times we finally got it to seat and build pressure.