I've used two sets of Durabond "Chilled" cam bearings in BB motors, one 4.5 inch bore World wedge block with B1 heads with a big solid roller cam and the other went into my latest 400 block stroker race motor. Both sets of heads have over 300 lbs. on the seats and over 800 lbs. over the nose
My 400 motor and the B1 motor will rotate over a bunch easier with the plugs out than any other wedge motor I've built with regular cam bearings in them with similar spring pressures
Roller cam bearings are suppose to be a bunch better than any standard type babbit cam bearings
IHTHs