bb crankshaft pulley numbers david knowles during engine re build i accidentally dropped and chipped the cast iron crankshaft pulley on my ' it still works fine but ever since i have been trying to find a replacement all the catalogs have them for what numbers are important to have on the pulley the ncrs judging manual does not go into detail my pulley has bm e gm cast in it the e has a box around it my car is an april ' david knowles