Looking up all the specs, it looks like the tripple is speced for a 118mm bottom bracket and the double a 115mm. Figuring 8mm chainring spaceing theory put everything in the 1 mm close enough zone. I was hopeing to leave the deraileur height alone as this might be a temporary change. The new large ring will have 4 less teath. Im not sure how much that changes the radius.
PS. Google tells me the diferance is 8mm, so dropping the deraileur is probably a good idea.

PSS. I found some more info and i'm going to drop off speculating till I get all the parts in hand.