Codman, Spool locker is a full time locker you should stay away from the full time locker unless your planning to just mud bog. It's going to make regular trail riding a pain. I also have a King Quad and it will hardly turn with the front fullly locked, kind of like driving to fast in the snow front end starts pushing or plowing with the wheels turned.
Here's a links to help you out.
<a href="http://www.paatving.com/Articles/highli" target="_blank">http://www.paatving.com/Articles/highli ... locker.asp</a>
Bottom Line
With a Detroit Gearless Lockerä, two drive wheels are normally locked together; however, the outer wheel may release and rotate faster than the inner wheel in a turn. The inner wheel remains locked, driving with full power at all times. Releasing an outer wheel in a turn promotes easier steering, reducing drivetrain stress and tire tread wear. If a wheel loses traction, it never spins faster than the wheel with traction, as with a conventional differential. "There can be no one-wheel spinout."