I have a 340 with a flat tappet cam. I used to use Rotella with the Hughes Engines zinc additive which is discontinued. Lucas Hot Rod oil is difficult to find out west which limits my options. Any opinions on Valvoline VR-1 high zinc oil?
Actually agree with Moparofficial and 66Jim, and Trailbeast. LOL
1. Use the correct viscosity. That's more important than the additive package.
- The oil pressure gage, temperature, and the tach will clue you as to whether the grade has the correct viscosity.
- If its a stock 340 with stock cam and springs, would not worry too much about the zddp. Anything over 800 ppm will do the job assuming the oil is changed every 2000 miles or so. If it's higher spring pressures or extended oil changes, then sure, look for higher.
2. Next oil change send a sample out for analysis. Do the same after trying the new oil. If the wear rates change and the use was the same, then maybe the new oil is doing a better or worse job.