I am not real familiar with Allis/Simplicity tractors, but I sure hope to be soon. I have a trashed transaxle in a AC B110. Broken axle tubes, welds, etc. It did have dual wheels and maybe that contributed to some failures. Anyhow, I am really liking the set up and was wandering what range and models of Simplicity's I need to watch for so that I can get a donor tractor for the complete rear transaxle assembly. Is there certain variations that I need to be aware of? My bevel gear box feels fine and nothing else jumps out as bad. Thanks in advance for any input.