As Bert said you need to space the top cap down from the spherical bearing so it can rotate/swivel without clashing with the top mount. Yes all the spring loads are going through the spherical bearing, yes it will wear out and start knocking. Sometimes they knock and rattle from brand new, but it's a track car right.
As someone said earlier in this thread, you might find you need to cut off the steering arm and flip it upside down, to give you enough length for the spring and its threaded adjuster. Sud/33's are unusual in having the steering arm on the strut leg, and it can get in the way. When we did this years ago we would put it all together and trial fit it with the threaded lower sleeve just sitting on the steering arm to see if the lengths, ride height, and clearances were ok. If you find you need it higher, the right sized exhaust clamp can be used to help set the position before welding.