Ok, so I just bought a 1987 Dodge D150, 2wd. It was an original 318 truck. Its got a 400, 727, holley 750, some big cam, trick shift kit, full Mopar performance ignition, and some other things, welds, exhaust ect...only paid $900 for the truck. Runs, drives, inspected. Anyway, my issue is this. When I start the truck up cold, it carries, according to the gauge, 80 psi of oil pressure. The warmer it gets, the lower the oil pressure gets, again, according to the gauge. (new sunpro). After it gets to full operating temp, the oil pressure, on the gauge show's 0 at idle, and 20-25 at cruising speeds, which is around 2500 rpm's or so. What could be causing this? From what I was told, the engine came out of a 1971 Dodge motorhome. It doesn't knock, doesn't smoke, and the oil hasn't moved from the same spot on the dip stick since I've owned it, 3 days. But, the previous owner said that he experienced NO oil loss, leaking, or smoking either. Whats going on? This is my first big block, and I'm kinda at a loss. Thanks in advance, and sorry that this is so long, lol. I'll post pics too. Definately the fastest thing I've EVER spent $900 on!

 

I would check how the gauge is hooked up. If you had no pressure at. Idle you would be having a lot of issues.

 

The gauge is hooked up using what I am assuming, is the orginal copper tubing. I pulled the cluster off to see if there were any leaks, and its dry back there, no leaking. I looked at the whole tube, and i saw no area that was cracked, or broken. I took it to a garage this morning, guy use to build race car engines, and he said I might just need bearings. He doesn't do engine building any more, but he gave me some numbers of local engine builders to call. So, I guess I'll be rebuilding it. :shrug: oh well. Anyway, here's some pics of it.