Lumps,
Best thing to do is go fly and record the result. Then YOU know what is correct.
As for Piper and their XX% performance for two mixture settings, this is not the only one. Makes you wonder about the accuracy or relevance of much more important data
"...the single drive, dual mags (J2BD)...". What a bastard idea that is. That's one of the reasons I like Colemill's (now Mike Jones) Panther upgrade of Navajos. The engine has separately driven mags.
Yeah……but the down side is the separate mags Vs the dual mags is that Lycoming and Piper never knew the undesirable result of going to the separate mags.
I bet everyone thinks the lower TIT was a good outcome
Probs not
Do you know what the static timing is on the Panther setup? Is it the same as the standard?