I thought the dash number for retainers was how many. Like 766-12 would be for a slant 6 for instance, while 766-16 for a V8. I think that's how it is. That said, I caint find a DANG thing on that 766 part number. Are you sure the number is correct? Not a typo? And have you tried calling Comp? I know.....usually worthless, but it's worth a shot.