Is there a difference in 4x4 cabs VS 2WD cabs? and other ?'s for the Pro's

[Brewski*]

Is there a difference in 4x4 cabs VS 2WD cabs? A/C VS non-A/C besides dash? Are there any differences in a manual VS 4 speed cab besides the high hump cover? What about the extra hole in the firewall is it a knock out? Is the interior color Parchment when it has white visors and door panels? If not, what is the color name? Did they ever come with a white dash pad?

[GMC71k20]

there is a difference in the a/c cabs besides the dash

[GMCPaul]

All 4x4 cabs the hump bolts in, 2 wheel drive only the big block and 4spd truck were supposed to get bolt in humps,
other than bolt in hump no differences between 3spd and 4spd manual trans trucks,
the hole was not a knockout for clutch rod but used either a plastic plug or a foam gasket behind a round sheetmetal cover with ears for a screw at top and bottom,
white visors and door panels are the interior color parchment
they never had a parchment or white pad.
GMCPaul

[GMCPaul]

Oops I missed that question GMC71k20
the firewall openings for evaporator boxes and heater core openings are different, and it has to additional holes drilled for the cowl flap door besides those additinal holes in the dash
GMCPaul