I saw a thread on ford trucks and thought it might be useful to some of you guys for a similar thread. I thought we would start with the 1/2 ton pickup. the 1939-46 chevy truck has a lot of parts at first glance look the same but in fact are not. i am a big fan of the 1939-40 truck which to a lot of guys is the same truck but actually has quite a few things that are not easily interchangeable. i think probably the best place to start is the cab differences. i am sure i dont know all of them and please feel free to add any i missed or have incorrect. The 39 dash was a thin flat plain panel that used 37-39 gauges. the windshield crank stuck straight out of the dash. the rear window is in a piece of rubber that is sandwiched by an outside ring that bolts from the inside. the passenger door has the external lock in the handle. The firewall is straight up and down with the strengthening beads running vertically. i also found this last weekend there is no drail holes at the bottom of the windshield opening. The 40 cab is similar with the exception of the dash is thicker , more rounded, and used a new designed cluster that had all of the gauges in one package instead of separate like the 39. The windshield crank is more vertical and comes out of the top of the dash instead of the front. the rear window mounts the same and the doors, door handle/locks are the same. as is the firewall. They did add the windshield drain holes to both sides in this year. The 41 cab started to change a few things. like the firewall, it was stepped out 1 1/2 inches for a bit more leg room. the firewall strengthening beads are in a criss cross pattern now. The cowl vent linkage and handle are really different than 39-40 the vent also operates a lot smoother. the door lock is still on the passenger side but moved to the door sheet metal like the car. i believe the lock cylinder is the same car to truck. the rear window bolts in the same, dash is the same as are the gauges. The 42 ( i think) they changed the rear window to a rubber pinch weld design. all other things are the same. There maybe other changes but i have only looked at (1) 1942 truck and not really close. the 46 i am not aware of any other changes in the cab from 42. Next i will go into the front sheet metal which is always a fun topic on these trucks.