No, no difference. However, Galen's book lists 71 HP 383's to have Carter AVS carbs, part number on the build sheet as #44. My 71 Satellite with the N code HP 383 with 4 speed and A/C, lists the Holley R4667 , part number 48 on the build sheet. Same 4160 Holley with or without A/C. The book does not list it as an HP, but it is. Galen's book is confusing with listing the Carter 6125S for the 71 383 HP's.