Mark,
I have a similar land situation to yours and bought a new Komatsu D31EX21, a 75 HP machine. So far I have spend 150 hours on it clearing and grading. What I have learned is that the new small dozers are very easy to operate with the joystick controls, but are much more effective at clearing than heavy grading. Depending on how moist the soil is, clearing large pines up to 16 -18 inches diameter is not a big problem, while hardwoods are much tougher even at half that size. The biggest problem I have had is in filling gullies and recontouring large hills or ridges. Moving a lot of dirt requires a lot of dozer, or many many passes with a small one. I have years in which to do this job on my gullied 100 acres, but I'm in no hurry and find the work very relaxing, and VERY FUN. Still, this is one expensive hobby. I have had no repairs as yet with the new machine, and this small Komatsu is very fuel efficient, burning approx 5 gals diesel per 3 hours usage.
One reason I bought a new machine, besides being insane, was that my experience with my Dad's two heavily used ones showed how costlyand timeconsuming the repairs of old models can be. I had to take a month off from school to help him overhaul an old JD450B, something I vow never to do again. From a fun point of view its hard to beat your own machine, but I'll bet its much cheaper and quicker to put the job out for bid and get a D6 and an excavator in there which will have the job done inside two weeks.
Good luck
Tim
