Background - '91 TBI 350, rebuilt the top half a month ago. I set the timing at 1* BTDC, replaced spark plugs, spark plug wires, cap & rotor, intake filter, coolant temp sending unit, and the O2 sensor. Problem #1 - Irratic idle with or without a load. Thought it was vacuum related but I checked all the hoses and couldn't find a leak. Also I can hear irregular puffs of air coming from the exhuast, almost like very weak pops but you have to have your ear next to the exhaust outlet to hear. Problem #2 - Engine runs very rich. Causes the truck to flood while driving (just enough to stall out and then have to wait 5 minutes to restart). I checked the EGR and it seems to be fine, also I cleaned the fuel pressure regulator the best I could. Could both these problems be caused from the timing being off? Timing is suppose to be 0* BTDC, but the closest I could get is somewhere between .5* and 1* BTDC. Any help would be appreciated. I'm trying to get my truck running good before winter hits. Thank you for your help.