HELP!!!! turned truck off, next morning wont start

this is puzzling to me I have a 1997 GMC K1500 5.7L and it was running fine and I parked it in the drive and went to move it a couple days later and it would not start....I checked it for fire and it did have spark but the spark plug wires were arching so I replaced them and the dis cap as well....it finally started and it runs fine sitting in the drive way......but when you go down the road it runs really rough...code po300 flashes up..multiple/random misfires....you can reve it up in the drive way and it is fine but driving it is terrible......wires are in the correct order and seem ok....i thought it might be the coil or the ignition module so I bought both of these but did not fix it...any ideas

Generally when the control module or pickup coil go, the engine doesn't run. Period. Sometimes with a bad module the engine will run fine for a while and cut out without warning. Check all of the wires again carefully, unplugging both ends of each and plugging them back in. If when plugging them in, you don't hear or feel that distinct "snap" then it's NOT plugged in, and will cause a misfire.

my 1997 gmc k1500 started misfiring and this is the weird part......truck was ok and parked it for the night and later went to start it and it would not start.....I checked it for spark and yes it had spark but I noticed the wires were arching so I bought new wires and dis cap and it finally started but was kinda hard to start....now it has muitiple misfire code po300 I thought it might be the coil or ignition module so I bought them but it didnt fix it..any ideas....:banghead:

Many things can cause this, worn dist gear, bad ign module, low fuel pressure, bad regulator. Start by checking FP, look for 60-65psi.