Between 1978 & 1981 I started a career, basic training, met "Wife Unit" and got married, did two years in NoVa. and lived in an apartment. In 1981 I transferred to the country, rented a house, and soon needed a mower. A friend saw a 1961 Wheel Horse at a yard sale, 7hp, 36" deck, 4spd., $75 … I bought it. In about 1989 after buying land here, no house yet here, I needed a little bigger tractor … coworker had a nice 1981 model Wheel Horse C85 he'd sell, 8hp, 42" deck, 8 speed.
For awhile I kept both, but neither really had enough power to mow well. In a few years, the 42" deck developed cracks, I spied a new unused 48" deck at a combination Wheel Horse / Triumph dealer, bought it. That 8hp was overmatched. I bought a B&S 16hp V-twin and moved 4 holes in the engine mount plate, fashioned an air cleaner using Kohler 7": filter & aluminum pot for lid, made a muffler of misc. pipe pieces, it was a easy fit.
Later as years passed, that engine developed heat issues, needed new heads as guides let loose, grass stopped up fins, so I bought another, put it in place, used a stove pipe elbow with screen to get cooling air intake away from front wheel area, the 16 hp V-twins use half the gas the Kohler 8hp did, never get bogged down by the 48" deck. I did fit larger rear tires on wider wheels with spacers I made. I also have chains for all 4 wheels and a 42" snow plow.
Just bragging on my old tractor, she's a horse. She drags tree limbs and branches well too.