If you can get a gasket, smear a THIN layer of black goo on one side of the gasket and let it fully cure.
Then put a THIN smear on the opposite side and allow it to cure until tacky.
Assemble the two parts finger tight and allow an extra hour or so to fully cure and then torque up the bolts...
I used to use that method,
Now I use Permatex #2 on the gasket, a thin smear both sides, just enough to not ooze out.
I'm having much better results with the Permatex than I had with the silicone.
Grigg