Interior Cab Dimebsions

[Richard2112]

This is a peculiar dimension to need but I'm wondering if the dimensions between the cab door jambs (behind the seat) varies between models such as the 10, 20 and 30's on our trucks. Measuring from steel to steel inside the cab, mine is close to 65.5 inches.

I am also wondering if these is much variance in floor configuration behind the seat where the fuel tank goes and if there's a height difference from the floor to the tank mounting nodes at the rear window.