Just wondering if there are any differences between the B18B1 crank pulley and the B20B/Z crank pulley.

Thanks.

yes you heard of "underdrive" pulleys right, well the b20z pulley is basically an overdrive pulley.

use the b18b if you can (unless you have a supercharger then the b20 pulley will give you more boost).

With a B20, would you change the crank pulley to the B18B pulley?

if its in a EG/DC or whatever yes i would. although i should mention that my AC worked real good when i had AC and the b20 pulley still installed (i have a CTR n1 now but ive used a b20b a b20z and a b18b pulley also)

size of the diffent belts the different cars contain to use due to chassis size, but the b20 is heavier. all motor go for CTR