When I pulled the engine out of my truck, the sludge in the pan was unbelievable, I don't think any amount of solvent or run time would have removed the majority of it. I removed all of the tin, scraped and degrease as much as I could, then more degreaser and a pressure wash. I put it all back together with new gaskets and seals. I disassembled the oil pump and cleaned it also. It doesn't smoke or use oil other than the rope rear main seal. I use 5w-30 or 10w-30 synthetic 'cuz I keep a bunch of it in stock, engine runs 38 psi oil pressure hot at 3750 RPM.
1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy
| 
