Cam re-grind

I will try, so bear with me. I am not a genius, so all I can do is explain it in my own terms.

Imagine the cam lobe being a triangle. Now, imagine that triangle on the cam core. A cam grinder can grind that lobe to end up most anywhere on the core he wants it. This is why you can end up with more lift and duration while grinding AWAY a camshaft lobe, because while he grinds it away, he also RELOCATES it in relation to the cam core centerline, as viewed from the front of the camshaft. In other words, the grinder can move the lobe on the cam centerline so that it will give more lift than before, even though he ground some off the lobe, because he MOVED the lobe on the cam centerline. Generally, reground cams may require custom length pushrods, as the base circle becomes less than it was originally. Sometimes though, new pushrods are not required, because some engines have a great amount of adjustability in the valvetrain. The slant six is one of those engines. You may not even require new pushrods. It is simply something you will have to measure for yourself to see.