Reply to Old Magnet:
Like most of the attachments added to the standard 7U model, they came from the loaders where the extra long track frame and large front idlers were used to aid stability with the heavy nose. When it comes to maneuvering with a dozer I think you are better of with the 4 roller....if your doing long run discing or ripping the 5-roller helps with the traction. You can have your choice but as usual you are trading off advantages and disadvantages.
Considering about $3,500 will still buy a decent running tractor with serviceable undercarriage that doesn't sound like much of a bargain to me.
Yo Ed! If I had to choose, I would take the 5 roller frame. I have a 7u with a 4
roller frame; my cousin has a late 7u with the 5 roller set up. The ride with the
5 roller frame is WAY better.😎 He has a blade for his and I never heard any
complaints about operating it. I have been on his 4 quite a bit....streching back
to this shot of it in action circa 1970 pulling a IH 51 Hillside combine. The ride
is better, and on the late 7u they went to a good DE start and this one had been "fueled" just a tad 😉 ( OK, more than a tad) Last time I ran this tractor for him was just a couple of years back doing some seeding.
[img]http://i37.photobucket.com/albums/e64/98J/ACMOC/IH51.jpg[/img]