So that's where the question comes in for me personally, because I don't race- street, roll, track or otherwise, but I drive very spirited around town basically daily. I have basic mods, gears & autocal tune. Tri-y's waiting in the garage and maybe a converter. I was going to leave the engine stock, only Dod delete (and therefore cam) if I have problems down the road. And I plan to keep this truck long term, I really like it. Engine seems to run great, minus crappy MPG. I blame that on the original 3.08s + heavy truck and previous owner, probably poor break-in. I bought it at 8500 miles, currently at almost 30k.

I don't expect anyone to make the decision for me, but I do enjoy this conversation, "with the experts".

 

Had I bought a 5.3 I would have cracked it open pitched the DOD before the motor ever cooled off as soon as I purchased it. Reason being is that when they do fail it is more often than not more damage done than just lifters due to circulating metal from the lifter/cam failure should it eat the cam.

 

I am thinking hard about ditching the AFM and putting a decent cam and tune after I sell my Firebird. Thinking real hard about a cam that will work with VVT also. And turbo........and convertor......Jeez.

 

This is exactly where I am, except instead of "sell my Firebird" it's "pay it off". All other things are the same.

I need family reliability mostly, and its sad that it could take internal engine mods to make it more long-term reliable, like 250k reliable.

 

Once modded it will be without a doubt more than 250K mile reliable. It's impossible to kill the 99-2006 5.3's they were 2,3,4,500K mile reliable in stock form and abused. Sure they would loose a oil pump every now and then but that's it.

 

It's not the lifters per say but the factory cam being junk from what I discovered. All of my lifters looked good when my 5.3 started to tick. One cam lobe was missing a chunk of the "case".

 

^ that happens occasionally on all engines and cant really be tied to AFM lifter issues. Ironically I have a 4.8 non AFM engine sitting in the shop right now with a lobe that looks similar. Was pulling a knock code we couldnt figure out, it was a center lobe, hard to hear audibly, but its wiped. Stoeck OEM cam 03 4.8

 

Had my DoD turned off for 60K miles, then out of the blue had a lifter fail, took the cam with it. I am much happier with a cam and tune anyways.

 

FWIW ....... maybe nothing, 2010 5.3 4.11 gears BB tune headers etc @ 5000miles now at 75K I kept my AFM and tweaked it to come in earlier .......... no issues and it tows a lot ........ the afm works great for me imo if you have at least 3.73 gears to keep the engine closer to the torque peak the afm is beneficial .......... the 3.08 trucks its useless ....... Lifters I understood that the brand / design of lifters changed sometime in 2010 so if you got the new design chances are you would not have a problem mine is a April build truck no idea what lifters in mine but so far its good .......

 

As much as Ive railed on the AFM lifters before a close friend as an 07 5.3AFM with over 200K miles in it. Not a single blip of trouble so far. Bone stock DD occasional tow sleds, boat etc but mostly a driver. He did buy it used from a dealer so we dont know if the lifters have been upgraded or not but its running champ, just thought to mention for others possibly seeking info on durability and stockers.