1974 D300 360 fresh rebuild will not start

Sorta 1 ton. Owned by a welder, there's some serious beef for suspension. She's had a lot more than 1 ton in her :). I did replace the original 2 barrel carb and intake manifold, I did not even know I would need a new cam/lifters. When I did research on cams it seemed like they were for much higher RPM vehicles than mine as far as where they make power. Divulge your knowledge, please!

It's OK to run your 4 bbl on a 2 bbl cam. Like you say the truck engines were set up for low end torque, 4 bbl is just giving it a little more fuel and air that it can handle with the 2 bbl cam.

Just helps me understand your engine build knowing this.