Volvo 760 rear suspension questions

[Swallowedhook]

I just picked up a 36k mile 1983 764 which had been garaged for decades. It first went to a brake shop prior to driving 450 miles home. Mechanic asked me if i had just put new shocks on it. I said no, but had noticed the car sagging in the rear and thought it needed new shocks. My research says Volvo used a lighter rear spring with the nivomats, and if you want to go with standard shocks you also have to change to a heavier coil spring. So I ordered sport springs 1 1/2 inch lower along with new strut inserts since the nivomats cost about the same for 2 new.