You could measure the dia of the rod material used to make the springs, and the number of coils, so that you can compare them against a set which is known to be stock. Keep in mind that the Sprint GT/GTV rear springs are always quite soft compared to the fronts.
As mentioned by others, I would also check for poly bushings. They are usually quite stiff and harsh, with little compliance/deflection compared to the OEM rubber bushings. Many owners have really degraded the ride comfort of cars by installing poly suspension bushings.
Personally, just my experience, but the best "all around" street shocks I've found for all our Alfas has been the stock Alfa shocks, and they last a long time. Regardless of brand, most aftermarket shocks are generally a little too stiff, trading away stock comfort for that extra stiffness. Even adjustable Konis I've used. Not that suitable for your ordinary crummy streets. The Bilsteins I later put on the Milano ended up being just a little too stiff, alas, causing the Shankle suspension to crash more than it did with the stock shocks by quite a bit. Might change them back to new stock Milano shocks, selling the Bilsteins.
Play with the tire pressures. That can make a big difference in tire sidewall stiffness and ride.
89 Milano (wife's daily driver since 1989, Shankle Sport)
91 164S (my daily driver since 1994)
94 164LS (~Q) (trip Alfa since 2000)
72 Morgan 27 (water time since 1976)
previously owned since 1964:
62 Morris MiniMinor 850, 67 Austin 1275 Cooper S (Downton 3/4 race), 64 Giulia Sprint GT (1st red one made), 72 Fiat 128 Sedan, 75 Alfetta Sedan, 78 Alfetta Sedan, 78 GTV, 81 GTV6, 86 GTV6
Last edited by Del; 02-11-2017 at 11:18 PM.