Th350's never had a problem breaking sunshells so a Beast wasn't made for the Th350. The biggest thing and #1 failure on the Th350 is the intermediate race gear breaking. You can get a hardened race relatively cheap, but get a good one, not a China made one. The stronger race will help the roller clutch (sprag) hold better and help keep it together, but I still prefer the upgraded drum and dogbone sprag. I broke several roller clutches in a Th350 racing. Finally I upgraded the drum and sprag and that problem was fixed for good. Then I snapped 2 input shafts and finally upgraded that to a hardened shaft. After that, no more breaking the Th350 with just under 600hp and a well built 3000 stall converter in a 4000lb truck with 4.56 rear gears.
http://www.ebay.com/itm/TH350-Outer...Parts_Accessories&hash=item1e5323dad2&vxp=mtr
You're right if he was running a 700r4 the Beast. There are to many things to list to upgrade a 700r4 to withstand that kind of horsepower, like the beast sunshell, sleeving the input drum and hardened shafts and blah blah blah and it still will not be strong as a Th350 or Th400 can be.
Even on very basic 700r4 builds, I like to do the beast sunshell, vette servo, wider 2/4 band, and a commercial Alto 3/4 clutch pack. That cures MOST of the most common problems and weaknesses for the stocker builds.
Some like to use the Raysbestos Z pack for the 3/4 clutch too as upgrade instead of the Alto Commercial Pack, and I'll put it in if they insist on it, but being that the real problem with the 3/4 clutch pack is overheating and coning of the clutches and steels, it doesn't make alot of sense to me to use even more 1 sides clutches that are even thinner yet and by theory you'd think they'd cone even quicker. But, the trick is keeping the heat down in the drum and that could be the purpose of the Z pack. I do know several that have had great luck with it.
