The reason that I need the motor to be stationary aND not "move" is because I want to install a sealed carburetor airscoop...
I'd go with the std. solid engine mounts
& use a rubber seal from the carb plate, to the underside of the hood
a little movement won't hurt you that way, it may torque a bit still,
but still redirect the air thru the carb for a cooler denser air/ram air effect...
If the whole front end is excessively torqueing/twisting/lifting ?
than you need to add forward bars from the cage to stiffen stuff up,
the chassis, even with a "elephant ears"
it wont stop the whole front end twisting...
It may even make it worse, think about it,
because the leverage points are father "out to the outsides of the frame",
it doesn't hurt you if you have forward bars,
it helps to transfer torque better thru the whole chassis/cage that way,
use the torque to your advantage...
It's wasted motion/energy that should be going thru the chassis
& getting to the ground thru your suspension otherwise...
Anyway
good luck