WICruiser, I built a 355 years ago and put in a big block oil pump only to help smooth the pump and distributor, the big block pumps have larger gears with more teeth and run smoother. I ended up pulling that pump out and installing a stock small block oil pump, no high pressure or high volume. Oiling troubling was solved with the stock pump. Just wondering if your 383 has a high volume and/or high pressure pump?

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