How much is a 17psi boost belt? I have the 17psi pulley and a machined snout just chasing belt to run it.

To give you an idea in regards to belt lengths, please refer to the guide in the link below. 

http://mace.kayako.com/Knowledgebase/Article/View/62/0/what-size-belt-is-required-for-my-pulley-running-the-standard-balancer

Please note that it is still recommended that you attempt to measure your required belt length using a piece of string and tape measure, as they belt length list in the link is a general guide only, and still require to be validated by the installer. 

If you can get back to us with a belt length you require, we may be able to assist.