Your 60 needs a 3x14" as the largest it will pull and the 70..NOT more than 3x16" My 630 is Fresh and Stout and labors in 2nd with 4x16" and my 720 D is about right with the 4x16"(2nd and 3rd). Our soil is average Clay, Loam with some Jack and Yellow Wax.. I am going to reduce one plow to 3x16" Semi-Mounted.
You can make your own adjustable Gauge Wheel with some basic steel parts, a wheel spindle and a welder.. I have made two and totally agree, the 60 and 70 MUST have the gauge Wheel to control depth.. My last 60 was an "All-Fuel" and would actually NOT pull the 810 3x14" in 2nd gear and 1st is NOT getting anything done..!! A 60 with a Power Block would pull 4x14", I am sure, but they all need GOOD tires and properly placed weights.. Ron.