ZDDP

Lucas products are high quality (in my experience). I've used the Lucas ZDDP adder shown in the photo above. Be cautious as one can add too much ZDDP. The 351W SBF with a flat tappet cam likes higher zinc/phos levels. I like to run 1,300 to 1,400 parts per million (PPM) of ZDDP. If the oil you use doesn't have enough ZDDP, the Lucas product works well to boost the levels.

Negative Effects of ZDDP -- Generally, high levels of ZDDP result in volatile phosphorus being transferred from the combustion chamber to the catalytic converter. Phosphorus can negatively impact the catalytic reaction sites in the converter, making it less efficient in turning CO into CO2.

JQ

I've decided to use Shell Rotella T4 in my newly rebuilt GT40 that goes in tomorrow. Its Zinc level is about 1200. Its what I can get easily and affordable here in Canada. (Royal Purple and Vavoline VR are hard to find and crazy expensive when you do).

I was going to use some ZDDP additive, Canadian Tire (think Pep Boys sort of) has this lucas additive. How much should I add to boost from 1200 to the recommended 1400?