I just recently (4 days ago) did a dod/afm delete on my 5.3. It has 176k on the motor and it never had any issues until one day a few weeks ago it suddenly started misfiring. I pulled over asap and went to a shop. They told me that it sounded like a stuck lifter. After a mere minutes, the misfire went away. No more nothing. Back to being quiet as a mouse. It really freaked out and confused the techs. The techs said that it would be better to be safe than sorry and do a DOD/AFM delete before anything catastrophic happened. No problem doing, my buddy and I spent a day doing it and got it running. We used an AMS racing DOD/AFM delete kit and used AMS racing .560 valve springs. I used a a stock style cam, just meant for the delete. Before any of this the motor was quiet as could be. Surprising for a 5.3 with 176k. Now after the delete, it makes a ticking noise, constantly. The tick increases in speed under acceleration, and ticks at idle, something it never did before the delete. The lifters came presoaked and specifically said not to soak before installation, which was odd to me since i know its a common practice to soak the lifters before installing. New parts I installed include the delete kit, valve springs, spark plugs and wires (since they've never been changed), and I ended up buying a driver side exhaust manifold and installed a new driver exhaust manifold gasket and flange gasket. Any ideas as to how to source the new found tick or quiet it down at least? Its not MY daily, so I hear all about it from her when she drives it and how she misses how quiet it used to be.