That u-joint looks like a u-joint that is used in a 3/4 ton truck.
Is your truck a 3/4 ton ?
I agree with Hotrod Lincoln, unbolt the u-bolts from the axle housing and slide the axle housing back until the
torque tube clears the u-joint rear yoke.
Once the the torque tube is out of the way.
You should be able to run a socket with a extension, inside the rear yoke to unbolt the front yoke from the main output shaft.
