What engine oil do you prefer,??.

For the past 3 years Royal Purple synthetic XPR 10- 40 , so far 14,000 hard miles , plenty of 7,000 rpm runs at the track . Used Valvoline VR 20 - 50 for break in . Used Total synthetic 10-40 after break in for 4,000 miles , but had to add ZDDP plus with that oil as it was low zinc .
I think if you have a mild cam any oil will do , but if your cam is over .500 lift with high spring pressure you really need the extra zinc .