Question I have is Callies offers a 4.5 stroke crank (BBC) but it comes set up for a 6.7 rod and not a 6.535. I called Callies and they said it was more popular with that rod due to the fact if they machine a crank to accept a 6.535 rod it take more heavy metal to balance. Would like to hear some opinions from some of the yellow bullet experts or novices does not matter. Also if I use a 6.7 rod will I still be able to get a piston with a decent comp. height? Motor will be probably 588 or 598 pump gas with maybe 400 shot on top that. Thanks in advance.