We bought one when they were new. It was a good tractor. They were available with 18.4x28 or 15.5x38 tires. We thought we were going to do row crop work with it, so got the 38" tires. We ended up doing field work with it. The 38's wouldn't hold it. So we eventually found some wheels and rims, and put 18.4x30 on it. Fully loaded, they worked good. It pulled 4x16 plows right along with an AC 185, but burned less fuel, and put out more power.
Ours was one of the hard starters. A whiff of starting fluid(built in injector) was needed on anything but a hot day. Never seemed to hurt anything. They upped the compression on later ones, which helped a lot.
The gear selection wasn't all that great for field work. The three range 6070 and 6080 were much better. I hated the antiquated PTO clutch/shift arrangement. And wide spread misuse of that prompted AC to put an external thrust bearing fix on the front of the engine.