I am looking into upgrading my LLY to a 6-speed....to increase the top speed

After reviewing the electrical differences between 05 and 06 VBs I am a little concerned the F Solenoid from the 06+ VBs will work sufficiently with the older TCM, as the TCM only outputs 100Hz, while the newer use 1kHz. The red connector solenoid will not like the 100Hz too much. While it will work, the pressures will be lower at 100Hz vs. 1kHz.
There is a good article on that:
ARTICLE
Might be fine when running stock power levels, not sure how well it will work with higher hp trucks.
Swapping the cables to match the older TCM looks straight forward if you compare both schematics next to each other.
Not sure at the moment if the 06 VB will be the better choice over the 05 with the modifications SC did (which I am not familiar with except for the 2nd tube added). At least when mofifying my 05 VB I know that 1-5 will work as before, only tweaking of 6th needed.