I tried running a short belt and it kept jumping halfway off my crank pulley and I never figured out why. I finally bought a smog bypass pulley but I parked the car and have not installed it. I paid $60 + shipping. I'll sell it if you want it, let me know before the weekend so I can pick it up when I'm at home. $50.
I paid $19 for my short belt, maybe a more expensive one would have stayed on better.