3/4" 30 x 3/4" 36. Fits later model 78 through 1980 Scout II's. This would be considered the small size. The easiest way to measure is to take a 3/4" wrench and try to slide it over the input shaft of the steering box...if it fits then this is the right size. The rag joint is typically the biggest culprit to loose and sloppy steering. So, check it out. There should be no play in the coupler. This is an OEM quality complete replacement not a cheap auto store repair kit or rebuild kit.
Scout II (1978-1980)