Just a suggestion. NOTE: I have not done this yet, but it is what I plan to do.
I just ordered a stock Mugen MBX6T body for my truck. (I have the old version, not the 09 spec, but the same thing applies...)
I've been running the Mugen rear posts, they're pretty effective in allowing for flex without damage to the body... but... they sit too high using the stock holes in the shock tower.
I don't like the idea of drilling my "pimptastic" aluminum towers. (Even when I upgrade to the new chassis I have no intention of running the carbon stuff- I wreck WAY too much!)
So... here's the plan:
I'm going to take some 1/8" thick aluminum and cut some strips about 1/4" wide. )I say "about" because this isn't rocket science... and I don't have a machine shop at my disposal.)
Then I'll clamp a strip to the shock tower and "match drill" the holes... move it 1 hole space, and repeat... and again a second time. That will give me 4 holes at the stock spacing, which incidentally the Mugen mounts fit correctly. Countersink the next to the bottom hole. Round the corners off with a dremel. Done.
A power miter saw with a carbide tipped wood blade is adaquate for small jobs like this- it goes through aluminum like butter. Of course a metal cutting blade is BETTER, but not mandatory.
The body mount is first attached to the aluminum part we just made, using a countersunk bolt... then the part is bolted to the shock tower through the 2 normal mount holes using regular bolts and locknuts.
NOTE: If you only want to go down 1 hole, only drill 3 holes instead of 4 and there is no need to countersink... just put the long bolt that goes into the body mount through the tower and the middle hole. If you want to go down the equivilant of 3 holes, make a strip with 5... again countersink the next to the bottom hole. And no need to countersink the bottom hole, the Mugen posts have a little plastic locating pin and attach with one bolt if I remember correctly.
This will give a lot of options for height of the rear post with a miniscule amount of cost (none in my case, I already have some aluminum left over from another "meathead project") and a little bit of time invested. A good excuse to play with power tools and drink beer. lol
I hope someone finds this to be helpful.