Hey guys! I am the owner of a 1972 S2 350 Mach II. I guess my first question would be about oil. On the oil cover it says to specifically use Torco T-2 2-stoke oil but all I can find is torco T-2r. What does the r mean and will I be able to use this oil from torco. Would I be able to use any other type of oil in it?