There’s no need to take off in granny low gear. If that’s a warner T18 four speed the first and reverse gear are straight cut and not beveled which can cause grinding of the gears if you shift from first to second while the truck is moving.
It has a 1965 grille but it could still be a 1966 truck since the 65 and 66 grille interchange. I mean it doesn't even have the right engine either so who knows.
