For a 79 Tiger AA5B O360AYK, the skyTec buying guide recommends primary: 149-12S and secondary: 149-NL. I called SkyTec and the rep said both should fit, but could not tell me the difference. He actually preferred the 149-NL (secondary). Does anyone have insight on the difference between these two models of starters? Is one better than the other, and if so, why? Thank you.