The early trucks were gas, and had shielded ignition for radio suppression as well as water proof for fording purposes. By the mid 60s, any further production was pretty much all diesel. The shielded plugs are available, but not at your Canadian tire store. The plugs will run from $6 to $15 each. The same plugs were used in the Jeeps, the dodge 3/4 tons, and the 5 ton gas 6X6, amongst others.
Canada had started to dispose of it's 1983 vintage 6X6s in the last year or so, but then sales kind of halted. They were sold as salvage though, so you might have to pull a fast one to get them on the road again. Ours were powered by the GM 8.2l engine, and an allison transmission, a very reliable combination. Some have hydraulic winches on them as well, and a few of the long wheelbase ones have wajax cranes.
Prefair surplus in Montreal was reselling the trucks for around $3,500 each.