They would of not designed/built a spread frame to accept the opposed engines if there was anyway to fit it in a wide frame.
Also the side panels will not fit.
I have built a some unconventional stuff, but never trying to stuff #10 pounds of chit in a #5 box.
Do yourself a favor and use a 14-16 HP single in a wide frame tractor.
If you want a twin engine go to the 82 series tractors.
If you want to hack it up, put in a small block chevy and be done with it.
