I have been looking at the specs for some of the older machines. I am wondering how they added so much weight on the same size chasis. For instance. My 642b 4000lbs, and the 743 weights 700 lbs more. They have the same dimensions. Thats alot of difference and the 743 only has 4 more hp. I cant imagine that just using thicker metal would make that much difference. Just wanted to get some other peoples thoughts on this.