Slant 6 to survive canadian winter ???
Back in the 1960's my mom had a 65 Barracuda with a stock 225 & a 3 speed manual transmission. It was never a problem starting in the winter. This was in Kansas & we had milder winters than yours but we still had some pretty cold spells. It was a dependable car for a number of years. My sister inherited it when she went off to college & kept it until she traded it in on a new car in 1978. I would think a Valiant/Dart/Duster etc with a 6 would be a great "beater" & wish I had one. I'd put an electronic ignition on it & keep the valves adjusted if it had solid lifters. Redjust the choke if necessary in the winter.