yes your best bet is to measure it yourself. each setup will be a little differnt from how you limit your suspension. dont forget about droop as well, this is where the 12" long spline kits come into play. stay away from the TG one like was suggested. many have had problems with the caps and joints failing.
call up jessie at high angle driveline. explain to him what you have and want you wantt to do with your rig. get the tape out and measure then have him build one for you. money well spent