installed new rear shocks, isolators = NICE (86)

my XR7 rode too low in back..
I suspected the springs had sagged over the years, or had been cut, so I got a set of nice used TC springs here NATO
sandblasted them and painted black

replaced rear shocks too; used the Gas-a-Just KYB-KG5556 ; they are pressurized so may give a bit of lift

searched wide for rear spring isolators and found these; very nice and look similar to stock
http://www.summitracing.com/parts/ENS-4-6101G/

removed rear springs ; looked like OE springs, that had a coil cut; the replacement TC springs were ~1.25" taller = ~ 1 coil

old OE ! shocks actually had a touch of pressure in them, and *some* resistance to motion

old OE isolators were bagged-out, some were squished right thru; fresh isolators may raise you a smidge

install was smooth ; the white KYBs look nice next to my freshly painted springs, I'll work on some pix

rear ride height picked up 1.5" so it's not a saggin' butt anymore;
rides firmer, I need to put couple miles on it in order to give an assessment of the new rear shocks

I like Summit = great service & prices

Ride Report!

First a big 'Thanks' to turbobike (mike) for selling me the used TC springs which I installed

yesterday, I put 80 miles of 2-lane twisties on the XR7 ; some gravel road too...
went to the beach with the kids (4 & 5) .. they Love the Cougar: "zoom car"

I am Really Liking the gas-a-just shocks ; they are firm and controlled, but it makes my front end feel looser ! I plan to replace my struts soon ..

Springs should be used to support the vehicle not the shocks. Seems as though, as you stated the original problem was the springs being in a sagged condition.