Unfortunately, you're also contributing to the bad info...He's close to the edge on the coast side, but perfect on the drive side...trying to adjust the coast side will only result in the drive side going to the edge. Backlash is what effects heel-to-toe pattern, and if backlash is in spec, then the heel-to-toe pattern is what it is, and isn't really adjustable.
Quoted from the Yukon install manual:
"IMPORTANT PATTERN INFORMATION:
The pattern's position to the tooth face (ridge) and flank (valley) notes the pinion depth.
Disregard the pattern's position to the tooth's heel (ring gear outside diameter) or toe (ring
gear inside diameter).
Gear patterns change from heel to toe, but in most cases an ideal heel-to-toe pattern is
impossible to achieve. Furthermore, the housing itself influences the heel-to-toe pattern
and the pattern cannot be changed without machine work. Trying to obtain a pattern centered
exactly between the heel and toe usually leads to frustration and a noisy gear set,
if the face-to-flank pattern is not correct.
Instead, concentrate only on the position of the pattern and how it relates from
face-to-flank of the ring gear."
