You mean 100 EGT, right?

Yep.

- Run high enough (8500 is pretty good) so you can run WOT. Back it off
about 1/4" of
MP from full throttle. Cocking the throttle plate slightly like this
helps mine.

I discovered this technique on my own, when I found it impossible to get the
six bars on my engine analyzer to line up at full throttle. To my surprise,
pulling the MP back JUST a smidge resulted in all six bars falling neatly in
line.

YMMV... I suspect the big six on a Cherokee probably has worse fuel distro
than the four in mine.

Yeah, I've spoken with a couple of O-540 experts, and they both say that 100
degrees apart is about as good as possible with the horrible fuel
distribution of a normally aspirated Lycoming six-cylinder engine.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"