Okay... So I did a tune-up today on the truck. It's a 4.3 Liter Vortec, VIN W; I changed the plugs to the AC Delco Platinums, wires were Autolite 7MM, Cap and Rotor button are Borg-Warner. I have never had a problem with this setup before, the only thing that changed are the plugs, they were standard AC Delco, now they're platinum. I think the wires should be 8.5mm, not 7. Also I changed the oil to Castrol Syntec with a Mobil One filter.

Basic symptoms are slightly-rough idle, rough take-off, and it eases out in high RPM. I think it may be running rich, all though I haven't driven it enough to tell or not. I didn't screw up the firing order I know that. Anyone have any ideas?

 

I found the answer! Timing is off, badly... the engine gets that "Whoop Whoop Whoop" when you rev the engine. There is some extreme lag between the acceleration and the response and my fuel economy sucks horribly right now. So my next question is, how do you time the truck?

 

Okay we've discovered other symptoms... apparently I have a faulty cap and rotor button so I am going to get those replaced today to see if that helps it.

2 Hours Later: Cap and rotor button replaced with AC Delcos. Helped some... there is a weird sparking or popping noise on the drivers side... maybe a loose plug. We'll see once the engine cools down.

Think its fixed... plug number one was loose with the wire causing it to miss. Once we got that fixed she seems to be running much better. Next thing is to top off the transmission fluid.