A Torq .21 will be a problem! Duratrax makes another head for it but, it is not any bigger then stock! Less nitro may work and the Torq .21's recommend nitro % is between 10-20%! I have to run my Torq .21 super rich just for it to run right (4 turns out on the HSN) and it runs cool at 220-230 under normal running and when I run it hard it gets up to 260-270. According to an article I read about nitro fuel (The quotes are from the president of Wildcat fuels). It said that in some cases you will run hotter with higher % of nitro if over the recommended amounts!
Here is a link to that article!
http://www.rcnitro.com/rn/articles/nitro_fuel.asp