it was running great I shut it off. started it up and noticed the idle was low I didn't think anything of it at the time.. when I get on the gas in drive or neutral the engine just boggs way down and sounds like it wants to stall it moves slow when i step on the gas anything more then halfway it bogs down

 

check the timing,if you have the 302 set the timing at about 12 degrees it will run great

 

Lots of possible issues.. Check for obvious vacumm leak.. Take a look inside and thru the air cleaner hose and make sure no debris is on MAF. and/or MAF could be bad.. Idle air control valve may be bad.. do an obvious look over... hopefully just a sensor may be unplugged or air cleaner box not snapped on tight..

 

What engine? 4.9 is infamous for running like crap if you have low fuel pressure.

 

Wouldn't the IAC make the motor idle up an high rpm if it was bad? My 92 idle high when it went out. U would think u was power brakeing the truck at a dead stop! I replace the IAC on mine and it idle back to normal

 

Could be clogged fuel filter, bad pump, or fuel pressure regulator also.