Thats a Cummins 275 with the roots blower, built into a 300 I think. He was probably going to a truck show. He has about 20 acres of old trucks and crawler tractors. He has a tourist attraction with an old saw mill powered by a one cylinder diesel engine "Huge" he cuts a board about every 30 minutes and is open year around. I love to go there, Jerome, Az.
Nick
Is that Alt US 89 he is driving near Cottonwood, AZ?