Stalling when put in gear

[C20Chevy]

I recently purchased a 1970 c20 camper special that has been sitting for a while after the original owner passed away. Its has a 350 motor with a turbo 350 trans, I work at a car lot and put it on a trailer and brought it over. Have had it in the shop and gone over for inspection, everything good only thing is the truck has a little issue with it stalls when you put it in gear until it warms up. I've been able to move it around just keeping one foot on the brake and feathering the gas, and once I get it going it runs perfectly fine and i can drive it normally. Any ideas?

Thanks,
- Mike

[davepl]

Adjust choke per factory manual.
Adjust choke pull-off door by bending metal pull-off rod per factory manual.

The choke itself doesn't have much calibration when cold, it's basically holding it against the choke pulloff as hard as it can. Once it warms up the choke spring (or whatever mechanism is used) will back off the choke plate, but until then the pull-off rod controls how open the choke is when cold.

If the pulloff is wrong, it'll want to die in gear, but you'll be able to two-foot it until it warms up, and that sounds like what's going on.

I'm going to assume you have checked all other basic tuneup items, no vacuum leaks, proper timing, plug gaps, rotor, cap, wires, etc.