got a p0300 code rough idle and runs horribly?

So, I was getting a cylinder 4 misfire code, changed spider injectors. Cylinder 4 misfire code went away. Then I got a p0300 code rough idle and runs horribly, went through all kind a different possibilities. Changed EGR valve, MAP Sensor, PCV valve, checked fuel pressure, checked fuel itself, checked rotor cap for corrosion, did smoke test, sprayed starter fluid to look for leaks after smoke test, has all new wires and spark plugs, tune up etc. but now today when I unplugged spark plug wires 2-4-6 from rotor cap, they all 3 have spark but idle does not change, runs no different. If I unplug 1-3-5, individually it runs even worse than it already is. So, it’s like the hole passenger side isn’t working right. Again, they all have spark, but 2-4-6 when I unplug wires from distributor cap nothing changes, I could unplug all 3 at same time and it runs off of only 1-3-5. Could this be an ECM problem? Or what? What do I look for next? If coil pack was bad, then they wouldn’t all have spark, right? I know it could be a vacuum leak somewhere but man I’ve checked brake booster, vacuum lines, intake, and smoke test etc., so, I’m pretty much eliminated that also I think. Please help, I’m ready to set this truck on fire. at this point I’ve been messing with it work almost a week now. These 4.3’s are junk man, truck has right at 214,000 miles. The backstory truck was driven from Louisiana to Arkansas. Ran fine the entire way got into Arkansas filled up truck again, got too plant for work worked a 12-hour shift, got in truck to leave and bam it had a cylinder 4 misfire, so my brother had me go pick it up with a U-Haul trailer and now we are here.