If you use epoxy and that includes JB Weld, be sure to sand the area on the fuselage or cowl where the exhausts will be attached. If not, epoxy will tend to pop off of a slick surface. If gluing directly to wood, fiberglass, etc. go for it. I've used canopy glue for small things such as this as it tends to have an excellent grip on most any surface. Gorilla glue would also work very well but you would have to use it sparingly and clean up the ooze before it set up. It would certainly be strong enough though.