Water pump question

Most of the cars with AC got the 8 blade, i would get the 8 blade if I were you.. Bet the books at the parts store are backwards, seen it a bunch. They used to say for 20+ years that my 64 Dart with a v8 had 11" drums, but if I tell them it is a 225 -6 then I could get 9" ers.

go figure!