[papajam]

Alfa used spring shims both front and rear in order to level the ride height. The front shims came in four sizes ranging from 3.5 to 10.5mm and the rears, also in four sizes, from 6.5 to 21.5mm. Your GTV may or may not have any shims. The front springs also use two rubber spring seats (or insulators), one on top and the other on the bottom, each about 25mm thick. The rear spring uses only one rubber spring insulator located at the top.
This pic is of the front. The rubber insulators are the black donuts at the top and bottom of the spring. Next are two thin pieces of sheet metal that fit between the insulator and the spring. The donut in the lower right corner is the shim(s) that goes between the insulator and the spring pan.