Will these forks fit my bike?

you will need to get an engineering shop to press out your stem & have it press fitted to the kx clamps, also your std kdx wheel spindle will need to be modified to fit the lower kx fork clamps (you could just fit the kx wheel & spindle ) while the kx forks are off you may aswell change the seals/oil etc even replace the fork springs to suit your weight...you say your kdx 220 is a 91????? ..kdx forks work well so long as you dont push them too hard..you`ll be surprised how well they work with a spring swop, oil change maybe re-valve.

I wouldn't bother with KX forks that are so old. Get at least some 97+ forks :-)

No such thing as a '91 KDX220.

Most of the responses have been as if the bike is a '91 KDX200.

OP's profile says he has a '91 KDX250.

That's a whole different animal than a '91 200.

IMO, you are better off using the fork swap money toward a newer bike.

Loved my old KDX250, but the stock fork settings sucked. On mine, I put in gold valves, stiffer springs and ran no pre-load. Cheaper and less hassle than a fork swap.