Did a 4 1/2' X 8' trailer for my uncle used a stripped down mercury villager rear axle 3300lbs rated!, I swear you could park a tank in this thing frame is 3"x3"x1/8' square tubing! (i think i over designed it a lil)
My Go-kart for some fun! used a 11hp honda, comet torq-a-verter series 40 primary drive and a #60 chain final drive, hydraulic disc brake mercedes benz caliper and toyota hi-lux clutch master for the brake master. Thing is soo much fun!