Spark advance issue

[mvfd70]

Been a long time since I've been on here. Glad to see this site is still up and running. Anyways, here is my issue. 1994 Chevy K1500 with a 5.7 TBI. Using TunerPro RT this is what I see when I'm under a slight load in overdrive. The truck runs terrible and has no power to go up a small incline without downshifting to a lower gear. Sometimes even drops to 2nd gear. The spark advance appears normal until the engine starts to lug a little bit then it jumps to this 23000 number. If I mash the gas and make it shift gears so the RPMs increase the advance will drop back to a normal range.