My question, why a roller cam for a slant six? For less friction or faster lift rates? If for faster lift rates, why not consider a "mushroom" tappet cam. Almost any cam grinder can do those, for about the same price as a regular cam (uses the same blank). Mushroom tappets are readily available (might/probably have to bush the lifter bore). I have a V-dub mushroom lifter right in front of me. Has a base of 1.120 diameter, body dia .742, lenght 2.065, push rod depth about .950 . It does look like the radius for the pushrod ball is smaller then the slant six dia, but this would require custom PR, anyway. The VW is not the only mushroom lifter available, either.
