Chevy!
Yep, mine is a 1957 Bel Air Sport Coupe, 383(not 283 lol), 4-speed, Cragars, etc. Of course, it needs $15K to rebuild, lol.
Sometimes I'd rather be spending $30 replacing my motorized bike's transmission, which I'm doing as we speak. I have 2 or 3 spare trannies, so zero cost.
The cost to replace my Chevy's tranny? Maybe $300, IF I'm lucky, $1000 if I I'm not.
You'll LOVE motorized bikes, so cheap to build, repair and swap engines.
And just like Chevy engines, 90% of rear-mounted bicycle engines have the same bellhousing bolt pattern!
Just like a hotrodder, instead of using the standard 1.6hp engine, I'm running a 5hp, high-rpm engine....powershifting thru an 8-speed transmission!
Once you run an engine with a shift kit, you'll NEVER run a "slushbox".