can any body tell me if a air compressor from a 8v92 will work on a 8v81 paul can not find a compressor and i have one from a 8v92 but do not know if it will fit please help
The short answer is yes, in a pinch.
You may have to change the drive dog on the compressor, but the shaft is the same. The only real variables are the compressor capacity and whether it is a truck compressor or an Eagle compressor. Truck compressors have the discharge and intake ports on the opposite side -- you can re-work the air connections to accomodate that if you have to, though.
The drive dog is pretty easy to change -- one bolt on the end of the shaft. Use a puller to pull it off of the shaft. The mounting is the same on both, though.