Curious front end issue. Ideas wanted

Orange car has stock lower control arms and front sway bar. the rear links look like they were replaced at some point but bushing look ok. the upper control arms and struts are adjustable RMS and bushing look ok. All joints are newish (10 not 56 years old) but the dust boots on the upper ball joints never fit right. Shocks are at least 15 year old KYB nothing specials and the springs are original 318 bars. Car was a base model 318 car from the factory.

When I bought the car in '11 it was resting on the bump stops and had a bent strut. When I replace them I tried to adjust them to the original strut length. Then I raised the front off the stops by a couple inches and had it aligned. Ever since the car stays a few inches higher than usual after jacking it up for work, until I drive it around a little and it gradually falls back down to position I set it at after a few minutes. It is really hard to "jounce" by hand. On curvy roads it handles really great. Problem is, I would kinda like to loosen it up for weight transfer when tuning at the track. What do you think is making the front end stiff like this?

thanks in advance.