Well, everyone was right, and I guess I knew it myself, that the truck was running to rich, but I confirmed it... I had not touched the screw since I got it home so I'd assumed that it was at the factory preset. I was wrong.
I pulled out the manual and it says that the stock setting should be 2.5 turns out from the the closed position... well, I screwed it in to closed and it went in 4 turns...
So, we went out to try it out again, but by that time all the other parts involved had been sitting in my car and my igniter was too cold/dead to light up the glow plug anymore... but just spinning it it sounded healthier... it's about 16 degrees here now and everything freshly charged, so if it warm up a little more I'm gonna give it another go.
Thanks everyone.