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An
M105-A3 was the last gen of the 105's. They are nicer and have surge brakes which are really nice, as well as parking brakes. They do have a cheap and flimsy landing gear that needs used with caution.
An M101-A2 / A3 (often listed under the M116 chassis designation) is proper size for use behind a vehicle and has surge brakes, parking brakes and 8-lug wheels which are very common. The A1 version has no brakes.
If you are just using on flat ground, the 105 may be ok, but
unless you have a BIG tractor its gonna be nose diving. On hills, I would not want one loaded down pushing my tractor.
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