The U bolts were about 1/2" too short.
I had to purchase longer U Bolts locally for 40.00 because yours were too short by about 1/2". The nylon lock nuts liked about 3 threads getting into the nylon locking ring at head of mounting bolts. So, considering I had to pay 40.00 more locally, after tearing down truck, so I could get back on road, they were not a deal. Very disappointed with Belltech. I have purcased half dozen or so products from their name brand and never had problems before.
Awesome portable compressor for the money!
I've owned and used (and worn out) numerous portable small compressors over the years (I'm 66). I must say that the VIAIR 85P is the best small compressor I've ever used. It is light in weight but operates very quickly and reasonably quietly. I would recommend it to anyone who needs a small portable compressor for their automobile.