[bl-is-future]

awe man, everything looks good except when i seen the word INTEGY. I have a thread somewhere when i built a FLM, INTEGY savage. Needless to say there is not a single INTEGY part on it now. Don't waste your money, them shocks shafts will bend like butter. I was warned too and didn't listen now i wish i would have.

Now for your questions -
uppers are adjustable and makes the truck very very very stable becasue the kit is wide. The drive shafts are also very tuff and have a great warranty. (it breaks you get a new one) The bulk heads do NOT replace your diff cup, you will still need the alloy ones (i rec. the HPI ones, have work fine for me) Gearing run the stock spur with a rc-monster mod1 16 tooth pinion. And as far as the 3 speed it depends on how you want to go. I personally locked mine in second so i could use motor brakes and reduce stress on the bec and no extra servo weight (not that it weighed a lot just a simpler setup, less to go wrong) I suggest you just lock yours as well. will actually having it shift you may run the risk of the tranny blowing apart from all the force of BL. Besides with that gearing 2nd is plenty fast enough, seriously it is quick, too quick for a track.
Hope that helped and good luck.