I dont have a pulling tractor per say, me and 4 of my buddies have old Craftsman's and we change the pullies around and weld up the rear axle's and eliminated the mechanical govonors, they go like hell! Every Sunday we go out in the woods and race and basically raise all hell. The most pulling our tractors really do is pulling eachother out of the woods when the break, out of the mud when we get stuck and once and a while we put a strap between them and have a little tug-o-war.
Glad to see there is another "tractor" guy on here, hahahahah