Is the splined shaft on a power steering box smaller than a manual?

Seems to be... thing is wobbling around, does not even remotely fit snugly. Didn't put the roll pin in yet because it seemed totally wrong. I understand that when you usually use these adpaters, you are converting to manual steering but in my particular case, I was making up for my steering shaft being too short due to a floor shift conversion.

Anyone else run into this? Guess I didn't realize there was a difference in the steering gear shaft diameters. ](*,)

I can use a manual box, I have a few hanging around but was attempting to keep the power steering.

Thanks,

- Greg