I am redoing a first year 60 that I plan on plowing with and am going to have plenty of questions! I guess I will start with the valves. what is every ones opinion on grinding the valve seats versus having them machined out and putting in hardened steel ones? Next, this one has rotaters on the exhaust valve retainers. I took them apart to see how they looked inside and the balls were wore flat. should I replace them? Is there much difference between them and plain retainers? It also has an after market power steering setup on it. does that effect the value of the tractor? Also, it has the shutter valve. are those worth the hefty price to redo or should i try to convert it to a thermostat? And the RH main bearing housing is behind the gear on the crank, and mine is STUCK on there. any helpful hints to get that gear off? thanks for any replys and I am sure I will be back on with more questions as time goes on!