I am trying to figure this out too as I know it says regular but if I use it I have a spark knock. premeium does away with it. But I have a few things I think needs replacing so I am working on it now


1987 Dodge Ram 50
2.6 5 speed
2 inch body lift 31x11.50 Swamper LTBs
4.62 gears lsd rear and welded front with lockouts
Weber carb waiting to be installed