I have a 99 silverado 1500 4x4, 5.3 liter, 23 gallon ( I think) and my fuel pump is bad. Whats the difference between TCU and TCF pumps? Can I look up my VIN and see which one I have or another method? I dont want to pull the pump and have purchased the wrong one. The truck was bought new from a dealer in CA, so it might have extra emission stuff on the vehicle.