Adam,

My guess is your fuel pickup did not unport, it was the power setting.  The Advanced Pilot Course http://www.advancedpilot.com/  teaches a descent technique I like.  (Legacy IO-550)

Say you are above 10K at cruise with full throttle and Lean of Peak.  Start a 500 FPM descent, then maintain Manifold Pressure within 1 inch and EGT plus or minus 10 degrees all the way down to Pattern Altitude.  Cyl Head and Oil temp will lower slowly and true airspeed will be easy to control, Fuel Flow will change very little. 

If you believe in Shock Cooling, CHT change is very gentle.  The engine is happy all the way down, you still have low fuel flow and pattern speed is not too far off.   Configure engine for pattern altitude and landing.  Works real good.

Steve Colwell