There is a procedure in the Chevrolet Truck Shop Manual for adjusting the universal joint ball seal to get the right fit. It’s tough to do while the engine and transmission is in but not impossible. Here is a link to the section of the manual that discusses it. You would need to drop the rear transmission crossmember to get the torque tube to drop enough to clear the tranny.
[Link].
Should you decide that this adjustment is necessary, here is a link to a previous post that discuss’s the dangers of disconnecting the torque tube.
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