Ken, I will see what Bert can tell me. I am just not sure what the guys are using. If there is a floor mount, that would work fine I suspect, or you can put in your own rail system. Mike
I took my mount design from one that I have seen used on Phil Thomas sport 20 hulls and beefed it up for the 45 power. Basically it's the mounting rails and rubber isolators of a Speed Master universal motor mount and then mounted aluminum angles to the bottom of the hull. You can get the rubber isolators from McMaster Carr.
If you need more detail let me know and I will remove the mount and take pictures for you. I did straddle the 1/4 bulkhead with my mount to get the engine where I wanted it.
Are you going to build a front radio box? If you are not i would move the engine further forward. The front radio box helps keep the weight forward of the CG to keeping the hull from blowing off. That's why I move my motor forward and reduced the size of the front radio box.
After the motor the next heaviest weight item in the radio battery. Remember the running hardware is along way in the back on the transom. It' s all about balance.