I needed a 42" 5 rib serpentine belt, for my latest project. Since a big nation wide chain store is close to my office I dropped in at lunch to pick one up. I explain what I'm looking for to the mouth breathing 17 year old behind the counter and he tells me that serpentine belts aren't sold by length but by car type. I told him that he's partially correct however the last three numbers on the belt part number are the length. He sneers and reiterates that he needs to know what car I have. I decide to play along and proceed to tell him it's a 1969 Lotus Europa with a Toyota 4AGE engine and a 45A John Deer Gator alternator. He stares at me gape jawed and then tries to type it into the computer. He didn't have much luck so he concludes that you can't get a belt for that car. I surrendered.
I dropped by my local NAPA shop, where they know me by name, and they grabbed a belt off the wall in about 5 seconds.

