Yeah, I did realize that the outer ring is adjustable shortly after I posted above, which makes sense since I guess expected pressures can vary. I finally found the time to replace the pressure guage today, and as I expected the new guage shows the same pressure as the old. But at least it's out of the equation.

Downstream of the DE filter
- Into Pentair multi-port valve model SM-20-2 (I opened this up - no blockage here)
- Out of MPV thru 2" PVC into Pentair Master Temp 250 heater
- Out of heater thru 2" PVC to checkvalve (says order number 172288 on it)
- Thru 2" to 1.5" reducer into Jandy valve actuator JVA 2444
- From actuator through chlorine feeder
- Into ground (still 1.5" PVC)
- About 22' to first eyeball
- Another 22' to second eyeball
- Another 20' to third eyeball (in spa)
- Another 6' to last eyeball

The pump is a Century Centurion 2HP model B855

I'm not real sure how the piping runs once it goes into the ground, so distances are approximate.