DOD delete parts guide - what is needed, and what goes wrong after?

What a proper delete includes: non-AFM camshaft, all 16 conventional roller lifters (not just the 8 AFM lifters), new lifter trays, and blocking the deactivation oil circuit (non-AFM valley cover or plugs); heads must come off, so head gaskets, head bolts and exhaust gaskets too.

Why the cam has to change: AFM cams have different lobes on the deactivating cylinders, built for the collapsible lifters. Normal lifters on an AFM cam cause trouble codes on those cylinders.

The oil circuit: either drive plugs into the four oil towers in the lifter valley and reuse the valley plate, or run an aftermarket valley plate with O-rings that seal the towers. Plugging the oil passages while keeping AFM lifters is not a delete: the collapsible mechanism remains and oil can back-feed into the DOD channels and collapse lifters later.

Oil system: AFM engines often run a higher-volume pump and a special pressure relief valve in the pan. It's common to go back to a standard pump and plug or replace that relief valve. Add GM oil-pan pressure-relief-valve cap (12639759) when deleting AFM to stop oil spray/consumption; replace the pickup O-ring.

Tune: PCM must be recalibrated to stop commanding deactivation; aftermarket cams also need idle, fuel, spark and torque-model changes.

What goes wrong after: most problems trace back to skipped steps — keeping AFM lifters with just plugs, reusing single-use head bolts, or no tune (codes and limp mode). GM head bolts are torque-to-yield; buy new ones with the head gaskets. Related: cost and what a full delete involves.