Ok so for an update, i stripped the entire motor down and noticed that there was a chunk taken out of one of the cam lobes. I'm sure the engine was dirty however i have a strong feeling that the oiling was a problem for the bearing failure. I noticed that i have a m63hp which is a melling high PRESSURE pump. Could this have been the cause of my rear main seal leak all along?

As for the bearing failure, it had that high pressure pump, no windage tray, and an el cheapo stock oil pan with baffling. Also i noticed the pickup tube measure like .6" or something, and the inlet was .56". Is this the measurements of the hemi oil pickup? I thought 383's had the smaller pickup tube. Did someone drill and tap out the oil pickup (if they did, they did a pretty good job)?

Can anyone determine if this oil set up could have been the cause of my bad main bearings? I looked around and it seems not too many people run the high pressure pumps. whats the deal with them on a semi hot street motor?

I dont remember what oil pressure it was running at, but its a 383 bored .40 over, pretty stock bottom end with speed demon 750 carb, holly street dominator intake, headman long tube headers, and full 2.5" exhaust. Yes i ran it very hard on the street.