Jon M.

Update: Rebuilt the top end: new VLOM, 8 new AFM lifters, 8 New standard lifters, 4 new lifter trays, 8 new push rods on all AFM lifters, 8 new exhaust valves and seals, 8 new intake valves and seals, all new high pressure gas lines, new injector seals and clips, new spark plugs and wires, new intake gaskets, new exhaust gaskets, new head gaskets, new head bolts, new oil pressure sender, new belt and tensioner. Everything reused was cleaned in the ultrasonic cleaner including the heads themselves which restored them to like new condition. Inspected the cylinder bores, still have cross hatching and no ridge. My son has been driving it without the AFM disabler installed, no problems. (update to update: had misfires on cylinder 6, swapped ignition coil with cylinder 4 and misfire moved to cylinder 4 indicating bad ignition coil. Replaced all 8 ignition coils with OEM coils ordered from Newegg) Ordered all the genuine GM parts online, perfect fit.

Ordered it online (19433052) and had it in my hand in a week. It is a kit that includes the new VLOM (12697806), 4 AFM lifters (12698946) and new fuel pipes (1 each of: 12696639, 12691176, 12677006, 12677004, 12677002). The local dealer told me two months to get it and it was $666 (nice fitting number for an AFM part). Found it online directly from GM for $429 plus shipping Total cost of parts to replace all 16 lifters and VLOM about $1,600. Plan to install everything on Sunday 1/30/22. This is my son's 2015 Sierra Crew and he already had installed the plug in deactivator but still had a lifter collapse within 2 miles after an oil change even with disabler plugged in. I am not convinced that the problem is entirely the VLOM but may have more to do with oil pressure or air entrainment even with the AFM disabler installed.