its not worth the time and effort to do it,find a set of used burgards or something,the ball joints on the stockers are junk and when they wear out,time to buy new a arms cause you cant replace them.
The one stupid Yamaha didnt do was put removable upper ball joints in the a-arms.
a little off topic but 87 warriors have removable ball joints they screw right out well sometimes haha
Not on the upper. Only on the lower.
I have done it befor on other bikes. I usually cut the arms about 2-3 inches out from the top and install a new piece of tube on both sides that is sleeved with a tube that slides inside and is 1.5" longer on both ends to spread the load away from the weld points. First bike I did it too was thrashed pretty hard for a couple of years after I did it with no failures.
uh huh...........................................it is just like building anything out of wood---measure twice, cut once.