Here ar a couple of pics and some words explaining the way i did it,(If you can understand it)
Simple realy,
If you look at the pics, the stem on the right are the remains of a zxr stem,i have cut the bit of the bottom just the amount that is pressed into the bottom yoke approx 25mm,put this piece in a lathe and bore out to be a press fit,
over the 3jt stem,also machine a step on the inside of this piece to clear the circlip on to 3jt stem,
now press this piece over your 3jt stem job done,you can now use 3tj cups bearings nuts washers,
Now with a zxr having flat top yoke and the 3jt having a stepped one,i don't know what affect this will have to the overall lenghth of the forks,I would like to know the length of the 3jt fpporks from the centre of spidle hole to the top of the leg,thats noncompressed,Off the bike.If anyone can help with this measurement it woud be a great help.
Ok i'v just found out the length of the 3tj forks is 71cm,now i need to measure my zxr forks,but i will have to remove them first.