Combination U joint.

I'm thinking of using a combination U-joint, I'm changing center sections and I don't want to take a part the one in the car right now, I have a 489 case but a the pinion is a 10 spline, my repalcement case is also a 489 case but it has a 29 spline pinion, the yoke on the car now is the smaller and the replcement is the larger one, i was told a 7260/ 7290 combination U-jointwill work. Any suggestions???

thank you