Driveshaft? Suzuki never put a driveshaft on the LT250R, they used a chain.
J/K bud, it's called the output shaft btw.

Use washers or cut down sprockets to use as spacers if you have to, might help to keep the sprocket snug against the snap ring.
I've never had a problem with it, forgot to install the snap ring once and rode it for like 15hrs without issue.
Don't think you're going to thread that shaft though, it's hardened quite a bit.