I have a 91 bird 700r4 2800 stall 383,when I put it in gear the idol drops and the car surges,and wants to stall,any ideas, thanks.

 

Does it hesitate when under load as well (driving it)? If so I would change the fuel filter first then if that doesn't help change the fuel pump. My 90 IROC did the same thing then after changing every sensor on the car I finally broke down and changed the fuel pump and that was my problem.