Forget the tuning school book added value, it used a 5.7 (LSA is ~114 & PCM treats full advance as ~125 deg) in their example, which is not the same as a 6.2/6.4 (LSA is ~120.5 & PCM treats full advance as ~134.5 deg). So that is why it should add up to 228.5 for a 5.7...for a 6.2/6.4 if you add them it should come out to 241. So on a 6.4 the PCM thinks full advance is 134.5 degs and you are running a 120.5 LSA cam with +14 degrees, therefore the PCM commands 134.5 degs for full advance (120.5+14=134.5) which is like Hemituna says in post #10. Knowing this and your cam specs (i.e. LSA, ground in advance, limiter) you work sort of backwards to find what the actual cam values.