Jon;
You are not the first and probably will not be the last with this problem.... I have heard of a number of people with the same thing... All running high volume
oil pumps and fairly heavy weight
oil, and mostly happens in cold weather when the
oil is thicker and harder for the pump to pump till it warms up and thins out....
Only suolution I know is to use a standard oil pump or lighter weight oil or both....
Going to extra pin or harder pin will put extra pressure on the cam and distibutor gears....
Sorry,this is no real help,but thought I'd let you know what I've seen and heard on other 351-C's,also seen the same thing on 460's....
David