I finally got tired of tearing my hair out over this, so the truck ran great for 50 miles on the test drive (I got it for the day), and I drove it decently hard to put it through it's paces. When I picked it up it ran like garbage, and by the time I got it home it wouldn't do 50 mph (the highway I was on was speed limit 60 mph), and it wouldn't rev over 2k RPM. In Neutral it wouldn't rev over 3k RPM. It has GREAT oil pressure, does not run hot, and shifts like butter when the motor is behaving itself, which is usually the second time in the day I drive it. It looks like a kid owned it at some point before me and put some edelbrock intake that sits on top of the the throttlebody instead of the factory one. So far I've checked all the fuses, all the fluids are where they should be and look to be about halfway between changes on all of them (will be changing them shortly) spark plugs, cap, and wires are all new, I need to take the cap off and look at the rotor, but it should be new. I don't see any oil when I look down the throttlebody, it doesn't burn oil, it doesn't burn coolant, and only steams when I first start it. There is no CEL on the dash. Can go get video of it doing it's thing if I have to, I'm just really tired of smashing my face against this brick wall lol.

 

Solved, after doing another 2 hours of research, finally figured out it's the cat, loosened the exhaust at the headers, way louder but it ran better, and got up to 40 in less than 90 seconds in the first time in forever

 

Yup. Cats will do that.......