Here is the difference:
Just a few parts are different and are "mostly" drop in fit.
The only part I changed is C4 in the bottom graphic; everything else is original on mine.
The nylon covered lower cam ("C") is a complete assembly and I did not change as it was beyond a "driveway" upgrade and cost almost what a new hitch was going for.
WARNING - THIS IS NOT A PULLRITE APPROVED MODIFICATION
As with all internet hacks (mods), proceed at your own risk. Pullrite will not even mention that this is possible and I will not provide any additional guidance (I have no wish to be sued at my age - or any age for that matter).
Here is the new manual for anyone who is interested in what the new hitch looks like.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW