go with a sqaure tubing up front....cost about 50.00 and you can decide your own slip length. that's what i'm runng on mine.
just make sure you weld 1/2" bead to each corner then grind them down slowly to where it barely fits in the other end to eleminate noise.
THE BEST PART IS THERE'S NO NEED TO BALANCE IT! try that if the problem persist, i know you'll be happy with it.