In 1984 "Chevrolet advertised the U.S. Army's purchase of nearly 30.000 full-size Chevrolet 4x4 Pickups and over 23.000 full-size Blazers with 6.2-liter V-8 engines"
(Standard Catalog of Chevrolet Trucks)
A few pickups (pre 81) with military options (black out lights, 24v starting system, tie downs etc.) had been on duty for the canadian Forces. No 1 tons, but K20's I think. And definately no diesels.
I saw one here in germany, but never get detailed information about it.
Walter