The stock tranny mount has all that dang stuff (mostly rubber) between the transmission and where it actually bolts to the skid. The 33 engineering mount gives you another 1 1/2" of clearance to push your belly pan up further. So if you simply removed the stock mount and replaced it with this one, you could leave your drivetrain in the same place but be able to raise your skid another 1 1/2" .... This is what allows you to go higher than skids that use the stock mount (Teraflex, Skyjacker, ext.) I guess you could use it with those, but you'd have to drill new mounting holes. And also, to get the maximum clearance out of 33 engineering's skid (1.25" below frame rail), you have to buy the skid and crossmember, 33 engineering's mount, and have a 2" body lift.
With their setup, the drivetrain will mount just above the frame rails and then that crossmember and skid will leave 1.25" hanging down. Not that much, but why pay all that money for less clearance? I guess the crossmember is kinda cool so you don't have to support th drivetrain when you drop the skid. My plan is this: 1.25" body lift (corresponding MM lift), sye and shaft (already got those), 33 Engineering trans mount, and a piece of 1/4" to go to town on. From the other guys who have done this set-up, they just clear the body with the completely flat skid. Only one guy as having contact, and he was fine with a couple of washers.
Check out the chart at the bottom of this page that shows the different set-ups with 33's skid.
http://www.offroadtoystore.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=33-1650