Unless it wants to tip over on it's nose it shouldn't need a counterweight over the tines. When I installed the HF 6 1/2HP on mine I had to add an extra 17 lbs to the existing counterweight to make up for the engine weight difference.
Mike

Dan troybilt never add 10hp too horse tiller in 1975 all where 6 hp who did that did good job so looks original. Biggest engine used was 8 hp 7hp used short time. All kohler have date code 1965 it was A 66 B and so on to 1975 was J if supply all info on data plate engine and include horse serial number off top transmission case not top cover right side above tire wire brushing clean dust out so number be read.

I've posted one picture that shows all the details gas tank mount, counter weight Lift rod reinforced. Serial no of K241
B051611 spec 46329D. I can fit the bumper guard off my kohler 7 inside this bumper guard. tiller is 1975 marck /april
I have date codes. Thanks