rms61moparman
Addicted to ArboristSite
6400, and when she-who-must-be-obeyed is not looking, you can easily swap the piston/cylinder for the 7900 version (<$200 and an hour's time) and turn it into a wood cutting beast.
With all due respect, they are a wood cutting beast to begin with!
There is NOTHING wrong with a 6400/6401 that needs to be fixed by installing a 7900 top end on them.
I know!
I bought in to the hype and went that route with my first one.
Did it get stronger? Yes it did!
Did it NEED to be stronger to cut what I cut.......not at all!
If you don't want to take my word for it, just ask that Mastermind guy.
Mike