You might want to go GOODYEAR instead, they are lifetime guaranteed on all their belts and hoses.....
a little known fact that they never advertise but that their retailers honor. Phil Swanson
> They are different for the 403 and the 455. Hoses: 403 Lower GM part No
> 2015465. 403 Upper 2015466. 455 upper GM 689922 (Goodyear 60964). 455 lower
> GM 689921.
>
> Fan Belts: 403 engine: air conditioner GM9433670, Gates 7603, NAPA 25-14983.
> Water pump & power steering: GM (3/8")9433640, GM (7/16"x42") 9433742;
> Gates 7450, NAPA 25-11303.
> Alternator: (original was a 15/32" x 57.5" but it is obsolete. Use either
> a 7/16" or a 17/32". GM 9433767, Gates 7570, NAPA 24-14483.
>
> 455 engine: air conditioner GM (7/16" x 62") 9433776, Gates 7619 or 7612
> (slightly shorter), NAPA 25-15733.
> Water pump & power steering: GM (3/8"x42") 943640; GM (7/16" x 42")
> 9433742; Gates 7450, NAPA 25-11433.
> Alternator: same as 403 engine.
>
> I found on my 455 air cond. belt that I needed the slightly shorter belt to
> get some tension.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM
