I don't know if the oil had anything to do with it, but when I pulled apart my pretty much stock 383 it had a failed hydraulic flat tappet cam. I used VR1 in it but the cam was in the car when I bought it. Bought it in 2008.

Built a 440 engine for the car. Hydraulic flat tappet cam failed - I do believe that improper assembly by the engine builder contributed to the failure. Put a hydraulic roller in the motor and then put the original 383 back in it with a hydraulic flat tappet cam.

Took a had look at the contents of the VR1 oil versus the Driven oil with my lubrication expert and felt more comfortable with the Driven oil. So far good luck with the Driven oil