I am in the process of installing a 350 engine (#14010207) into my 1983 c30 3+3 dually. I want to slam a cam in first. What cam would be best for towing?? I was looking at a summit, and they have several options available. The engine is stock as far as I know. How do you calculate the lift and duration needed for best performance???? Does anyone know what the stock L&D numbers are for that engine??