ORIGINAL: Andrew
...I think my preference would be to rely on mechanical attachment rather than epoxy - I like JB Weld, primarily because it is so tough.
I won't offer any thoughts regarding using JB Weld for this particular application, but Norel at one time did use an epoxy of some sort to affix their carbs to the engine.
One property of JB Weld is that it will soften if heated sufficiently. As such you could always heat the engine in an oven to about 300 and pull out the NVA if you ever wanted to.
(I have used JB Weld to repair the plastic radiator tops of two different Toyotas that I have owned. On one car it held fine for years. The other car must have run hotter as the JB Weld would soften and fail. I ground off and redid the repair twice - then did the smart thing by giving up on the repair idea and replacing the radiator.)