That one is pretty scary. I’d stick with something lower to ground with 4 wheel made a go cart with the same engine and clutch used a straw chopper shaft from a Massey 510 combine cut it in half made a transmission with chains and sprockets as that shaft has woodruff keys machined in it every 2 or 3 inches it’s also common size for pillow block bearings and self aligning side mount bearings. Fooled with the ratios till I got it right boys run it into the ground it was a hoot.