U joint size

Am I correct in thinking cars fitted with the 7.25 from factory would of had the smaller u joint 7260?car in questions is a 70 dart.

Only asking as the 'new' 8.75 that's going on is 7260 and if that's that case it should all match up once the shaft is shortened. And I won't need to mess about getting a new one etc

If it's not, and they differ how do I measure the u joint to work out what size it is?