I've got at least one lifter going out, which (I think) is why my DoD hasn't been working. I've decided to go the "replace the stock parts and just tune it out" route because I don't want to spend more on the engine than I did to buy the car.

The problem is, I've only got one reliable part number for the DoD lifters (12680871), and I obviously want to replace them all at the same time. Does anyone know the other GM part number I need? Thanks.