Code3 has listed their new mid-sized pulley for use with the 178mm crank pulley on their website. It's not in the SRT6 section yet, but is in the C32.

http://shop.code3performance.com/pro...3&productId=22

They are also coming out with a lighter version of the current SC pulley:

http://shop.code3performance.com/pro...=3&productId=4