360Dust, yeah they cancel each other out to end up at around 1.6. The lifter bank angle gives up around .010 lobe lift. Were you checking with a solid lifter? Moparhead, the stock hyd. roller lifter anti-rotation hardware needs the top of the lifter bosses milled flat, in addition to the "spider" mounting bosses. I've been running a set of ported R/T's on my 408 for a couple of years now and have been very happy with them.