badboy,
Going to the 6 deg front castor block will also increase turn in dramatically over the 10 deg castor blocks. The 6 deg are standard on the 04-R and the 10 deg are standard on the 04/04-pro. Aurra is right, if you want a ton more turn in, run the 1-ways!
Aurra,
You were correct. the Tamiya rims are stiff AND indestructable!