Mancini is a great company to deal with. Had problems with what transmission fluid to use in my 727 since Mobile One changed their formula, and by the way you cannot mix the dark colored plastic bottles with the light colored plastic bottles of Mobile One because the formulas are not compatable, so says Mobile One. However, since I live close to Summit Racing I went to talk to one of their sales reps about what fluid I should use. His first question was "What is a 727", this coming from a salesmen that I had seen their for many years, alarmed me. We discussed this for a while and he went through some catalogues on the counter, and after a while, I had to excuse myself and do my own research. I landed on Castrol plus 4 and all seem to be working fine, normally would not buy Castrol Products due to John Force, but I had no other choice. By the way, I understand that the Summit Salesmen does know alot about stereo systems. Thanks, HEMI JOE