Do i need to add anyhting to my oil or gas to make my '72 cuda 340 run better? I hear new oil doesn't contain zinc and is rough on the cam and that lead additive keeps the engine from getting too hot. Any merit to those items?
Unless you are running a big cam with a lot of spring pressure the zinc thing is not a big deal. I have never put any additives in my stock 70 340 at all and have had it sence 1991. Would be a little extra insurance though and could not hurt.