Truck Repair: 86 Chevy 305 carb adjustment, vacuum leaks, chevy 305

Question
I have an 86 Chevy short box 4x4,with a 305 in it and an automatic trans 700R4 and the carb has never been right since I've owned it. I tried adjusting it many times and never seem to get it right on its sweet spot. Either it idles too high and runs good or idles good and wont run for crap in gear. I suspect maybe a rebuild for it but everthing moves freely as far as I can tell. Do you have any tips for adjusting it or maybe it not a carb issue? Thanks for your help.

Answer
In a carb overhaul kit is a sheet of instructions that give a step by step adjustment proceedure, and following the instructions exactly is the best way to be sure they are correct.
Make sure there are no vacuum leaks also, and that the accelerator pump in the carb works good.
Van