Just found this group and thought I would introduce myself. I'm a recent retiree and last summer I was introduced to the sport of Garden Tractor Pulling. I must admit I have enjoyed it and the people I met very much. I had inherited a 1975 JD300 from my father in law about 10 years ago so I did some minor modifications and used it in GT16 class (16 hp, bar tires). Had a lot of fun but was not too successful. I learned that this was harder than it looked.
Picked up a beat up 1968 JD112 without an engine that I plan on restoring and running next year along with the JD300. Here's a picture of it with it's new Vanguard engine. I'm currently rebuilding the transaxle. At least for me, designing and building the tractor is more than half the fun.
PS It's amazing what you can do with a saws-all