Being a single pattern cam, this is an easy way to check the adv/ret of the cam. Get #1 or #6 cyl on overlap @ TDC, ie both valves open. Put a straight edge across the prods of the cyl being checked. If the cam is advanced [ ie, ICL is a lower number than the LSA ], then the int prod will be higher; and vice/versa. Swap prods in case the lengths are different. When I say 'higher', that is referencing off the crank centre line.
Couple of things to note. This test is not as accurate as putting the straight edge across the lifters. And the difference in height is very slight, about 0.030" or less. The point is though that if the int lifter [ or prod ] is higher than the exh, then the cam is advanced. The accuracy of this tests depends on the accuracy of finding TDC.
