There is a Flat head and a Top Heat type
Note, if you are using a New STC’d Pacific Oil cooler, The flat top vernatherm will not work with the new POC oil cooler. I already tried it and the bevel inside the oil cooler will not allow the vernatherm to go down far enough to seat.
I am using the top hat version, and it apparently has a similar problem. On a test ground run of 5 min I detected no oil leak, but .7 in the air it was obviously leaking oil at the gasket. No way I’m going to spend another $800 for a new Vernatherm.