Post the TP data log .xdl file so we can see what's going on.

Do you hear any knock,ping etc...? How's the motor run? Any other truck noise?

One thing to look at is does the knock sensor match the knock module in the Memcal? There are a couple differant ones, manual and auto. I'd go back to all stock knock settings or even a fresh bin to start. Loose the 10* across the board timing for now so we have a benchmark, then a data log would be even better. But any data would be good for now.

Some systems just keep retarding when something is wrong, either in degress or knock counts. Like a short or broken wire, check contiuity from knock sensor to pin at PCM.

Also if you have over tightened the knock sensor at some point in time? It's shot! They squeze shut and always think theres knock. Do you have any other noise? Yes exhaust rattle, motor mount vibrating, etc... I understand no knock counts, but for some reason can still have retard... seen it but don't know why?