4.3 v6 1997 Chevy 1500 missing at slow speeds

ok guys need some help. 1997 Chevy 1500 4.3 V6, it had a coolant leak on the intake and while it was in the shop i had them do a tune up,plugs,cap,rotor and wires. It didn't run bad before all of that. Well after the tune up it had a little miss, upon checking the coil was arching. So i changed the coil and module along with the MAF sensor and fuel filter. I have checked fuel pressure and it is perfect. it still had a small miss, #3 plug looked a little wet so we changed the fuel spider in the intake. so again after all this it still has a small miss at slow speeds around 30 mph, at half to full throttle no miss only at slow speeds, so people i REALLY need your input, also checked compresstion its great truck has 136,000 so PLEASE HELP

The thing to determine is this:

is the miss caused by ignition (weak, blowing out, drowned) or by fuel (to lean, too rich)... also check for airleaks.