Hi Chad- Should only be 6 of them, right? 3 rights and 3 lefts? They go on the intakes and increase the valve lift on a stock cam because the ratio is 1.5:1 instead of 1.4:1. (if I remember right) Thomas, Barker, B&B and Fenton all made these in the '50's. One problem I've noticed with old magnesium when redrilling old Halibrand wheels is that it gets real dry and brittle when it's old. You may have a higher chance of breakage, especially if used with stiffer valve springs?
