At one time, diesel oil was a good alternative to oil that had reduced levels of ZDDP for emissions reasons, but diesels are low RPM engines with different detergent package needs. The calcium detergents in the oil are antagonistic to the ZDDP, so the balance has to be correct. Brad Penn, and Joe Gibbs Racing make oil with all the right chemistry for older flat tappet engines. Use one of their oils.
1970 GS455 Stage1 Race weight 4025 lbs.
TSP 470, 602 HP, 589 TQ
MT headers, Gear Vendors Overdrive
Best E.T. 11.54 Best MPH, 116.06
1998 Riviera SC3800