Does the load on the engine change what rpm it taps out at? I'd pick a 15 degree hill to check that... If you have that environment where you are...

 

Fascinating problem... Thinking more about the rev limiter... check out this video:

Would be more telling if it were a Ram.... but reading the comments I found out the subject vehicle is a 2005 300C - which ships with a 5.7 hemi. Probably same all the controls as the RAMs. His seems to limit right under 4k RPM.... coincidental?

 

Exactly! I did see one video where you turn key to start position while you drive and its supposed to disable speed and rev lim. Unfortunately for me it didn't disable the rev lim, but I still suspect the rev lim!

I think they are different pcms, my 05 Durango reads a lot more things on the scanner than my 04 Ram does. I can even read EGR position on the fly in the Durango, Ram comp doesn't even show me that.

 

Start looking at the PCM pin outs to figure out which wire would send that info, see if you can tap into with your DMM. Have a factory service manual? They are free, and on the web. There are pages of connector pin outs in the FSM, might be able to get a handle on which wires are coming from where.

Maybe you pinched a wire when you were doing the lifter job, or tugged on a connector and broke a connection.... or maybe the PCM is shot... I had one in my 04 1500 that insisted the O2 sensor was bad. After swapping sensors, tracing and checking the wire to pcm... I bought a replacement pcm, no more O2 issues after that.

 

Its been a week since I've had time to work on it and today I bought a brand new crank sensor for it (instead of using my known good crank sensor) and.....STILL NO CHANGE!

However my next plan was slightly more ambitious, I swapped a complete fuel injector rail with a completely different set of injectors from an extra hemi I have and the engine is now overall running worse, however it did rev up to 5000rpm though slowly, then backed down to 3900 rpm vs the 4100rpm wall. Idle was very rough. I'm now going for broke and am getting ready to throw the kitchen sink at it!

In light of that I've settled on the following courses of action:

#1. Verify fuel injectors are clean and working. Replace As needed.

#2. Buy Replacement pre-programmed to VIN PCM from ebay.

#3. Verify timing....

Now on #3, The reason I have this route at #3 after buying a new pcm is because I'm completely confident in my ability to time an engine (I've timed hundreds of engines) and honestly it couldn't be simpler than on the Hemi, however my cam pin was broken and I custom made one out of a drill bit end as my new pin, I'm worried it may have wobbled a bit in the bore of the cam pin face when I torqued the cam bolt, and may have timing slightly off. I felt pretty confident in the fix when I did it so I doubt this wobbled at all, But to be honest I'm just retracing every step I've done trying to find this problem and I'm probably over scrutinizing everything hoping for a cure. Another reason I'd buy a new pcm over doing this one, is because I feel like the crank sensor and cam sensor would throw a code and be off, and also if there were any type of small difference it would be in the pcm's margin of error to compensate for. The other thing is, I can't see taking an engine apart unless I have a clear reason to or last ditch effort. If all else fails I'm upgrading the cam.

My heart is screaming injectors and PCM at this point, but I have doubts. Truck ran great until cam pin sheared last year, I rebuilt it 2x now to still have this problem.

To recap for everyone:

Compression in all cylinders is 175-187psi
Idle Vacuum is 18 inches
Fuel Pressure at all engine speeds is a very steady 61psi (58psi under full throttle)
Ignition light test verified all coils are working to at least some capacity
Power balance test showed all fuel injectors work to at least some degree at idle (I feel like medium and high duty cycles are in doubt)
New Plug Wires & Spark plugs
New intake gaskets with a thin permatex coating to keep water out of cold gaskets (standard practice on all my plastic intake manifold hemi engines to prevent hydrolock).
As of today all vital sensors are brand new.
Wiring and harnesses are all in great shape.
Recently Fuel trims looked great with my original fuel injectors, however I never did see them under wide open throttle, fuel trims currently look like **** with this fuel rail.

 

So you say the spark timing looks right throughout, and you seem to have fuel... What is going on with the throttle plate as it approaches the wall, is it really still wide open? Lack of air input controls your rpm pretty good

I guess I could see a retarded cam causing you some issue, but if you have another hemi you could put a degree wheel on it and measure one of the valve openings and compare against the one in the truck.

This is an interesting link, but unfortunately no one updated with the solution.
http://www.thehemi.com/forums/viewtopic.php?t=796