brother has a hybrid. was stock swingarm for a while. the stock swingarm was great for trails and MX, but the new +4 is great for duning and drag racing.

It isn't that hard to put a 500 into a 250 as it has been done so many times.

I know a guy selling a 500 engine for $500+shipping. Just needs the top end to back together and a clutch cover.