haow much doe a 1950 3100 weigh? I removed the old 216 today and that thing weighed a ton. it put as much stress on my hoist as a 7.3 ford diesel does

Actually, the online Chevy shop manuls here on the websote have this information.
The specs that are posted are for the ADS series starting with 1947 2nd edition and going to 1953, and then the slightly revised specs for the 1954 and 1st edition 1955. You should use the 1947 specs, as your 50 model will not be much different than the 1947 (changes in weight were very minor, as evidenced even by my 1955's weight versus the 1947.
Chevy was careful to specify TWO different weights for each model.
The "shipping weight" is the truck, with NO options, but ready to drive, except for NO gas and NO engine coolant. This was used probably because shipping companies did not allow fuel and coolant in evhicles in transit.
The "curb weight" was the weight with the engine coolant and a FULL tank of gas added. Be careful. The capacity of the early tanks was, I believe, 16 gallons. But, on the 1954 and 55 AD trucks, it was 17 gallons, so there IS a difference.
The Chevy manual says for your 3104 (pickup configuration of the 3100) with NO options:
Shipping weight 3230
Curb weight 3360
Note that BOTH numbers include a spare tire, as that was standard eqwuipment, and not an option.
Note also that the 54 and 55 models were actually a bit LIGHTER:
Shipping weight 3115
Curb weight 3255
And, by the way, I have been doing some weighing as part of my SLURP project (see under "Dispatch"), and these weights are actually ACCURATE.
Jim G