Yes, they're both useful. If the 8hp has a 1" shaft, the clutches are expensive. You can use a torque converter and have a bad machine. Or you can have the crank turned to 3/4" and a keyway milled. The 2hp engines are great for kids minis, with 4" wheels and 60 tooth rear sprocket. You could even use it with 5 or 6" with a bigger sprocket, or use a jackshaft to gear it down for power and very low speed.