1G car stalls when put in gear

[JayB98GST]

ok, my car sat fro over 3 months because of bent valves. i just got the head rebuilt and i put it back on the other day. at first every time i put it in gear the car would idle roughly except in reverse, which it would stall right away. now everytime i put it in gear the car stalls right away. this is a 1g nt automatic. any advice would be greatly appreciated.

 

[JayB98GST]

if i put it in gear right after i start it, when the rpms jump about to about 2k for a second, then it wont stall, but it will idle roughly. then if i take it out of gear and put it back in it will stall. anyone have any ideas? i dont know what else to check.