Hi, planning on running 100shot nitrous setup this summer and also plan to purchase a higher stall TC, and several TC companies make nitrous specific TC for mega $$$ of course!
do I need it? My car will hopefully run mid 12's, maybe low 12's if I can hook..
what will happen if I overload the TC?

:rockon:

 

you will ruin the converter, which will ruin your tranny. I hope you dont have much money in either one, cuz they will blow to bits if you got high Stall + nitrous. 100 shot MIGHT be ok, people run 100 shot on stock stuff, but with a high stall there is a HUGE SHOCK from using nitrous, which can blow a TC in 1 hit.

 

I would assume by "higher stall" that you mean "higher than stock" but not excessively. How much are you talking about? 2400-2600 RPM or so? Your heads, intake and cam don't need much stall.
Nitrous specific converters have antiballooning reinforcements and are designed to withstand large nitrous hits. 100 hp is not really considered a large nitrous hit. If using 250-300 hp or bigger shots it is well worth the money to get an antiballoning converter. A stock converter that doesn't already have some problem would be fine on a hundred shot, and a quality made performance converter should be fine with a 100 shot as well. If you for some reason intend on using a 3000-3500 RPM or higher stall (although I wouldn't know why with a dual plane intake, mild cam and vortech heads) then a higher quality converter would be a good idea. Chances are you wouldn't hurt it right away, if at all, but over time the case may balloon, and if it does the converter will diminish and fail.