You need to pull the valve cover. look for anything out of normal with the valves . Was it smoking? My bet is the head has to come off....
Mind reporting status of "knocking"? I'd like to file this sound and your findings in my organic memory file. Thanks & hope it wasn't too bad...
Sorry to hear it was that bad. Didn't sound good, but didn't think it would be that bad. How many miles were on it? You did the right thing, especially if you love the truck. I know what you mean "classic" have had my 99 since 5/01, just (after starting in April) got it registered as classic. 3 yes back had all metal and paint done, $10k, it ain't going anywhere without me. Are you back on road yet? Where'd you end up having work done?
Replacement head wasn't done correctly. Valve seats dropping on anything newer than 05 is a rare occurrence, sans outright abuse. Early 5.9's had issues dropped valve seats due to seat composition and insert clearances. However, a bad injector can have a detrimental effec ton head just as well as a piston.
More like a series of threads and findings over a space of time. If you are keeping it stock chances for issues are low. However, if you are running a tuner to make it perform like a 325 with extra power then the potential exists for problems.
The seats and valves were updated for the 04.5 release and again for MY 06. Basically a slight change in materials to handle heat better and tighter tolerances on the seat fitment to the head. That allowed for more heat soak in the cylinder which is what will get to the earlier heads when you try to push it to hard. If it is an HO you have less of chance of problems, and SO has more things to consider and watch.
Noted, shes an 03 H.O. 6MT, I only have power plans up to my clutch specs, 490 hp, 880ft lb. I'll just be trying to get there on near stock components and tuning. Nothing crazy just chasing fuel economy and torque.