Engine Hesitation at light throttle!

I'm trying to get my truck back on the road after sitting in my drive way for a year. I would turn it on every couple of weeks or so but no driving. The truck was dying out on me while driving, no spark, turns out it was a bad oil pressure switch. Since fixing that problem truck starts every single time. I have replaced various items in an attempt to bring it back in good road condition (timing module, pick up coil, ignition coil, AIC valve, EGR valve, checked ignition cables, checked ground to ECM. Set timing to 4 BTDC with the EST wire disconnected. Now the problem is while test driving the truck it will idle fine and hold idle while in gear but when taking off it will bog down after a couple of seconds. Sputters and bucks and won't completely stall. Whats strange is it idles fine and takes off just fine for at least the first couple of seconds. I checked the VSS and looks good. One thing I have noticed is after I reconnect the EST wire the timing retards a boat load! Maybe 20 degrees or so, Help!!!

350, TBI,,