Anyone remember the cab-over Ford pick-ups of '61-'67? They had a several-hundred pound slab of pig-iron between the gas tank & the bed for added traction, not only in the winter! When I owned one of those Ford cab-overs, I went to the University of Michigan library and pulled some research documents from their stacks about the need for putting another Chevrolet product in a good light-the Corvair cab-over pickup. It had a side clamshell door that folded down to provide a steep ramp for side-loading, since the rear-engine, rear-drive made a rear platform much-higher in the rear of the truck than the bed platform between the wheelbase. The document I found was a Chevrolet internal document sent to sales staff at dealerships showing a side-by-side comparison of the Corvair van-pickup and the Ford. There was a picture of the Ford being picked-up into the air by 3 men with overcoats (winter photo) who were lifting the rear bumper. The front doors of the Ford were open, as I recall. The 3 guys that Chevrolet recruited to lift the rear of the Ford cab-over pickup looked like the nose tackle and the defensive guards from the Lions front line-plenty of beef there! The point they were making is that the Ford was nose-heavy, and that the Chevrolet van had better weight distribution. After I found the sales memo, I researched further and found that Ford added the rear counterweight to provide more rear weight for traction-compromised conditions like wet or snowy driving.
I have a friend in Montreal that used to weld-into the rear bed of his pickup every winter a big piece of scrap iron, and in the spring he would cut it off. Crude, but effective.