'01 Silverado 2500 with the 8.1 vortec
 

Just bought a 2001 2500 with the 8.1 it seems like it's missing when at a red light but seems to have plenty of take off power and it's slow to shift gears ( it's 2 wheel drive By the way if that makes a difference) , also the tires seem a little oversized. Any ideas?