833 OD slip yoke info.....

I am makin progress on the rat truck. Got the transmission mounted on the Hemi. Discovered the slip yoke I have is too big and slips on the output shaft. The transmission came out of a early 80 D150. Which slip yoke do I need, preferrable for a 1350 U joint? Is it 26 or 30 spline? My eyes are too dang tired to count them little splines. Thanks.