Recommended Synthetic OIL

[98 SNAKE EATER]

regarding the use if diesel oil, I did a little research and found this.
Diesel engine oils have a higher anti-wear (AW) load in the form of zinc dialkyldithiophosphate (ZDDP). The catalytic converters in diesel systems are designed to be able to deal with this problem, while the gasoline systems are not. This is one of the main reasons you don’t want to use a diesel engine oil in your gasoline engine.

Yep, I'm pretty sure the Delvac I've been using is the cause of my melted cat

No worries now that they're both gutted though