So I think I solved a 15 year old mystery about why my truck doesn't run quite right.
The previous owner overheated the engine when he let the radiator freeze, him and my dad then met up at a shop my dad worked at and rebuilt the engine, and I remember my dad mentioning that they used all leftover parts from other projects and they didn't have to buy anything. 15 years later I find a forum post stating that if someone uses a crankshaft from the wrong year of GM 4 cylinder in my specific engine block everything will fit properly but the sensor ring on the crankshaft is slightly different which will cause the ignition timing to be too advanced, and will cause the symptoms that my engine has. Of course there's no way to adjust this, but I have some ideas in the works.