To answer your question Stan it's mostly trial and error. If I were you I would get the heaviest bar you find and go from there.........
Couple typical issues I've seen with these bars on off road rigs are the splines stripping out and bars break as stated earlier. First don't use aluminum arms. Hip get steel arms!..Second use the longest bar and longest arm you can make work. Offset the arms if you need to to make a longer bar fit. This way the bar itself will twist less at a given wheel travel. Also retorque the bolts often that clamp the arm to the bar and use lock nuts. On mine I also put a snap ring on the end of the bar with a large flat washer. This helps keep the arm in place if the bolt comes loose..
great advise and i was gonna get steel if i had to get a new set. Jason C alerted me to where my setup was from originally so i just ordered a new bar and bushings for 1 3/4" tube as im out of 1 1/2" tube. i figure ill run what i have till i strip the splines then ill get steel arms.
any advice on the actual set up?
eg:
do i center the connecting rod from the arm to the axel on the axel?
how bout up and down placement on the arms in relation to the axel?