Serpentine belt for my 91 5.0

[burnout50]

Replacing my belt on my 91 5.0 with A/C. There's two part numbers in the belt catalogs. One says (dealer air) #875K6 the other one says (factory air) #905K6. Which one for my car? How can you tell between dealer air and factory air?

 

[Roland69]

I would get both and take the one that dosn't fit back.....But I would guess you have factory air because not many people added air to thier mustang they usually took the system out

 

[burnout50]

Cool, I'll try the factory air part#

 

[stangbear427]

IIRC, the part#'s are measurements. One belt is 87.5", the other is 90.5". Take off the belt and measure it, and buy the closest one.

 

[bryce93lx]

i think it has to be the 90.0 becuase i run a 87" with my smog delete