which is a better cam bank for a all out race motor? 39* or 45* .with a roller and without

 

39
45 is for "3/4 race" motors

 

In principle, the 45 degree would be a little better because the pushrods are straighter up from the lifter. In practice, it doesn't matter, and the best would be the .921" lifter blocks which were all 39 deg.

 

i have been build a 496 for years now ,and i came across a 66 425 block ,whicj has the 821 lifter and the 45 degree angle and i also have a 70 455 with the 39 degree ,which has been the pig for this build. and i havent place them side by side yet,and compared thickness, which of rumor of the 425 is a thicker block. and if the 425 block is thicker ,this may become an option and just keep the other for a spare or anther build ,i just have really heard of any one or read which would be the best for a high performance build.thanks for the replys