Insulation in the rear air inlet housing, or wing to fuselage cavity?

[Dan schultz]

I have the insulation in mine, the aircraft used to have the JB air conditioning system, don’t know if that has any usefulness.
Dan
P337-0168
N67S

[Kim Geyer]

My thought is the insulation in the rear inlet is to prevent oil canning. One of our Skymasters was missing it and popped a bunch of rivets on the top skin. All Cessna singles I’ve worked on over the years have had insulation in the armpits

[Rick Erwin]

Thank you for the input guys, now to figure out the best thing to do ...

Rick