Truck is running 'ok', idles ok and drives down the highway fine, no knock detected. But..low end is nonexistent and I am wondering if this can be remedied by modifying the timing in the main spark advance tables to look more like that of spark advance tables from a zr1 tune? It is currently using the timing tables from the 2000 silverado 5.3 stock tune. I have not found a tune that has zr1 cam in a 5.3 but I have seen many with z06 cams. How different are the zr1 vs z06 cams?