B&M lists on their own website not to use anything less than the 70266 when bypassing the radiator cooler all together. Its harder to mount but doable, its what i run and i dont have to worry about pink milkshake ever!
First page 6th bullet down.
http://bmracing.com/wp-bnmcont/uploads/bm_cooler_techdoc.pdf
Interesting pdf. B&M recommends temps 180-200 AFTER cooler.