Moose, one thing I found online was that large slow powerful motors really need metal engine mounts. Prolonged running generates significant heat & timber or plastic mounts tend to fail when they get hot.
The Chipmunk has a full metal mount all the way from the firewall to the motor. One section bolts to the firewall and the front section that holds the motor is adjustable via 4 bolts (two each side) so the up/down and left/right angle of the motor is easily adjustable.
If you cant find one on line then I’m sure one could easily be made with some aluminium plate.
Here is a link to one similar to the Chipmunk, for the price its not worth making one.
This one is by far the cheapest (from AliExpress) but eBay & Banggood also stock them, just a lot dearer.