Hi!
Agree! Dave Brown has the best engine mounts!

This is how I do it!
Just bolt the engine to the engine mount with self tapping metal screws or drill and tap the mounts and use either 3mm, 3,5mm or 4mm screws depending on engine size.

Second: Take the mount/engine and hold it against the fire wall and see to that it lines up with the fuselage sides . Most of the time the engine should point straight forward! Then spot glue the mount on with medium or thin Ca glue using accelerator.

Third: Drill holes through the mount into the firewall, put in blind nuts from behind, and screw the mount firmly to the firewall...That easy! I usually don't remove the mount after glueing it on!