Weight alone does not matter when comparing 1959 to 2009. I owned a 1951 Chevy 1/2-ton pickup. No seatbelts, no crumple zones, no safety glass, drum brakes, Armstrong steering, Legstrong brakes, and vacuum-activated wipers. Going uphill in a rainstorm was always fun. Wipers pretty much stopped.
6-volt electrics, crap headlights, one taillight, no turn signals. It weighed in at a whopping 3,375 lbs. I dare say a modern Silverado 1500 4x2 weighs considerably more.
I even owned a 1966 Nova and a 1967 Nova. They were identical in dimensions/weight, and the 1967 was safer than the 1966. 1967 added a padded dash, safety glass, collapsible steering wheel.
It was billed as a mid-sized economy car. The Nova weighed between 2,520 to 2,885 (station wagon) lbs. It would be comparable to the Toyota Corrolla, Hyundai Sonata, or Honda Accord (maybe Civic) of today. They all weigh in over 3,100 lbs.
2017 Toyota Camry - Length 190.9", height 57.9", width 71.7", weight 3,240 to 3,350 lbs.
2017 Honda Accord - length 192.5", height 57.7", width 72.8", weight 3,170 to 3,605 lbs.
Hyundai Sonata - length 191.1", height 58.1", width 73.4", weight 3,250 to 3,589 lbs.
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Your ‘51 Chev PU needed a new fuel pump for the wipers to work under a load.
The top portion of the pump was a vacuum booster that was capable of keeping the wipers operating, if its diaphragm was not ruptured.
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