the Viking was offered in the 40, 50 and 60 series and was mainly used as a bobtail either with a 261 or a 283. The Spartan series was offered in the 70,80,90 and 100. The 80 series which had a 348V8 with air brakes was the only entry that really caught on. Of course it had only been a few years that Chevy had been in the business of selling trucks larger trucks and most of their dealer network was not geared to service anything larger than a 2 ton. The 2 tons were used a lot in the Midwest as farm trucks. They seldom got enough miles to need an overhaul. The 80 series found a market of a cheap way of getting a truck tractor. Instead of being overhauled like heavier trucks like International, etc. the Chev big blocks were considered throwaways and engines were swapped every year. When the 409 was introduced in about 1961, 348 engines were replaced with 409 engines. They would blow the doors off of a 671 Detroit, got about half the fuel mileage and needed a replacement engine about every 100,000 miles.
I scrolled through the Spec manual and was surprised to see that the 322 Buick was still listed. I would assume that it was offered in the 70 series which never gained popularity.
