Hi!
That engine is one of the most powerful .46 engines on the market. Very good engine and reliable too! But get a Dave Brown plastic motor mount for it! The alu mount you showed us is no good!

Just take a round dowel and stick and glue that inside the motor mount holes you now have and then Ca glue (spot glue) the new plastic mount where you want it. Then drill holes with a long drill bit through the motor mount holes into the fire wall and then remove the mount.
Redrill the holes a little bigger and put in four blind nuts. Secure the blind nuts by screwing in 4mm allen head bolts.
Then take the mount and fasten it to the firewall with long 4mm allen head bolts!