The aftermarket insulators are harder than my original insulator that I bought from a fellow Stovebolter. Seems like mine has coating that helps seal. It may just be varnish from years of use, but it helps the insulator seal perfectly.

The new plastic insulators also have a mold mark in them that reduces the contact surface. If you want to run an aftermarket insulator without gaskets, then I suggest lapping it with ~150g sandpaper attached to a flat surface to get it perfectly flat, even if you leave some of the mold mark.

I haven't seen any aftermarket insulators that do not have "dimples" or "slots". If there is no dimple, one can easily be cut into the plastic with a Dremmel or drill.

Useless info: I bought three aftermarket insulators for my 235 w/Rochester B. None would work. The port for the power piston on my carb is in a different location than the dimple on the insulators. The mold mark on the insulator prevented me from cutting a new dimple. (My port is like a 216, but the carb has the correct size throat) I had to cut a dimple in the bakalite insulator; no problem, works fine.

- Lonnie
My '54 3104
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lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt.

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