First let me give a rundown. My freshly rebuilt Magnum 318 is cursed. Standard rebuild parts replaced, rings, bearings, oil pump, timing set. When I first fired it up, there was a coolant leak at the rear of the intake that was contaminating the oil. Fixed that. Next, the oil pump locked up. Replaced it with a standard volume pump. Then I lost two lobes on the flat tappet cam that was in there, so I put the stock roller back in it. Now I have what sounds to be a bottom end knock at idle only. When built, I measured bearing clearance at .0015" on the rods, and .0015 on the mains. The original bearings looked great when removed. I'm running the same trans, converter and flexplate as the before. It only knocks under 1,000rpm. It has a little knock that's more pronounced at startup, but as it warms up, there's a steady "thump thump thump" that has the repetition of an exhaust leak, which leads me to believe its on one cylinder only. But 90% of the time its there, with no noise on decel, and no noise revving it up or at steady cruise. There is also a vibration above 3,500 or so. I'm am running a neutral balance converter though. Is it possible to have a rod bearing on its way out as a result of the oil pump locking up? When it happened, I had to idle for roughly 1/2 mile or so to get it out if harms way. But it runs great other than that. Any ideas??? It's not a big deal to drop the pan, but I figured I'd get some input from the masters first