A stock tailwheel from Van's will fit if you cut the end off and turn the end of the shaft on a lathe to remove a section of the taper in order to fit the tailwheel weldment. My RV-6 kit circa 1993 came this way and that's what I did to retrofit the full swivel tailwheel.
We have put our full swivel tailwheel on several of the older, bent spring, non-swiveling tailwheels. We can even do the machining of the spring for you.
Check our web store for more info on our tailwheel.
Put my tail wheel fork on I got from Vince recently. Fit perfectly and is a very nice peice of workmanship. Also put the Vans tailwheel pant on. Anything to go that little bit faster.