1974 D300 360 fresh rebuild will not start

Looks like a 1 Ton Dually, 2 wheel drive, 4 spd. with the flatbed.

360 engine, did it have the 2 barrel carb and factory 2 barrel intake manifold on it when you first got it ?

Wonder if it is still the factory 2 barrel cam and lifters on it yet too?
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!