I now have 2000 miles since i put my Comp 260 cam in my 1973 318. During those miles, i used Valvoline VR1 Racing oil 20w50, mainly because of its higher zinc. Can i back down to a different oil, probably with less zinc? Would 10w40 lower my oil pressure noticably from 20w50 when the oil is warm? I have 21 psi when hot in neutral and 45-52 psi at 1800-2000 RPM when hot with 20w50. The motor has close to 90,000 miles and 2 rockers on the right side are a little worn and make a small click when the motor is warm and the oil has thinned a little, which became a little more noticable after i did the cam, valvesprings, lifters, and timing chain. This was most likely the result of taking them off and putting them back on. Motor runs strong though. What oil would you recommend and the weight inorder to minimize the oil pressure drop when hot. If i could get it thinner for the morning startups, it would be ideal. I have been running Napa Gold Filters. Thanks.