Only set I've ever seen. The STC is attached. I guess the proper name for them is "thermal inserts".

Attached Files
SA1814NM.pdf (121.38 KB, 15 downloads)

N18506 C-150L overhaul project
N5275G C-310A flying ecological disaster
N37BZ fast wrong way 150
N383FM kerosene burning insanity
N55HL you bought a what?