my ke20 weighed 850kg. that was with a 4age, t50, ke55 borgy diff (a LOT lighter than a hilux), small surge tank etc, gauges, different seats. it did have heavy wheels though - 15" chasers. i reckon i could have saved 7-10kg a wheel by having proper lightweight mags.
AND no tools, no spare tyre.
so 850kg for those cars with a hilux diff and decent gearbox was a way conservative guestimation.