This is the first I have heard of this, I never had mine done with the pcm swap or cam swap. I thought the pcm would relearn its self, I also thought that the tune would tell the pcm what needs to be changed. Just wondering cause I am swaping my complete drive line and power plant here soon. going with my 6.0 and 4l80e tranny set up.

 

i geuss just remimber ecu and eng need to be calibrated to each other so any time eather one is changed it should be done regardless

 

Just spoke with the man himself (I swear the guy returns emails almost as fast I can send them, absolutely one of the most responsive guys I have ever dealt with) and just to be clear for those guys like me, that may have just had him tune their stocker PCM - It is only recommended if its a replacement PCM. If its your stocker and you have no issues or lights, no need.

I only post this because that question popped into my head when I read the thread and their might be others that wonder as well.

Last but not least - DAMN happy with my tune. Not seeing a big increase in mileage, but I did not specify wanting the mileage tune as I though it was always included in the tune but perhaps it is not. Either way, truck runs strong all the way up to burying the speedo at 120

 

Only needed if it's a replacement pcm.