I agree with those who say such a modification would not be good use of your time and money. If you want to make art - make art, but don't expect the art to do work. If you want to do work, buy or rebuild a machine designed to do that work, or equivalent in forces/loads and strains.
My first lawn tractor was a 1970 MF14, which was built like a tank - great frame! I never broke any part of the structure of that tractor. I noticed that other similar sized lawn tractors were not built as well, and even regular mowing work was resulting in cracked frames [stamped pans]. As I carefully reviewed the structure/drive/systems of light tractors (many of which were nothing more than a powered lawnmower that looked a little like a tractor, I could see that in the interest of competitive economy, manufacturers were building machines that were exactly nothing more than the advertised capability required - no reserve strength nor power to enable expansion of use.
As for drive, for a light tractor, four wheel drive is really helpful, if you want to pull or plow. If not four wheel drive, at least have differential lock, so when you get stuck trying to pull too hard, you can get yourself out. The aforementioned MF14 lacked diff lock, and was a pain when I got it stuck in soft ground - second machine required anyway.
I love "projects", and I like encouraging others to explore their innovation strengths for all the positive reasons mentioned here.... But, you can get a lot of time and money into a project which then fails, and provides no return to you, and os nothing more than art. If it's the art you wanted in the first place, you've got it. But if you wanted a working tool, you wasted time and money.
