My best advice is either 1 buy a carrier off a 03+ blaster bc they are Hydro brakes or 2 find a Banshee Rear Brake Setup from the Pedal back and cut and weld to install it.... Ive never heard of 660 brakes on these but if your any good at fabbing you shouldnt have a problem doin nething....
My rear hydros are off a '04 660. I just made a bracket to hold the caliper, weld a tab to mount the master cylinder and extend the brake lever. Couple hours of messing around. I use the stock rotor and rotor hub. The calipers are the same for raptor 660 and warrior and I do believe they are the same as the shee. If you got a '02 or older blaster your going to have to do fab work anyways so you can use a caliper off of just about anything.
Someone correct me if I'm wrong, but I believe the caliper's are all the same. '03 and up blaster's, warrior's, shee's and raptor's. Anyone of those caliper's should work for you
keep looking on ebay for setups off of different quads (banshee, warrior, raptor, wolverine, etc.)
thats how i picked up my 660 master cylinder for $5.