Alright this is an interesting mod, so I went to a wrecking yard and pulled a set of rear springs from a 1992 Mitsubishi expo LRV sport fwd 5 seater [aka: 2G Colt Vista/Expo /Summit wagon], for micah, seeing as how he already procured a set, I decided to try them on my fwd 1987 colt vista [aka: 1G Colt Vista] well here is some pictures to help tell the story.
pictured Above: The 2g Expo rear coil, on the left, notice how it's much thicker, and a little shorter, then the 1g vista spring, seen on the right, I took both top rubber insulators, One from my 1G vista, and another from the 2g Expo, and they fit perfectly on both ends of the springs fully installed... Why you may ask, well because the bottom ones almost always deteriorate on our cars, plus more insulation on the springs makes for a less clunky sounding suspension.
pictured above: is my stock "87 vista spring setup, and Pictured below: is the 2G springs with both upper rubber insulators installed.
I put the wheels back back on the vista and took it out for a spin, first impressions are in, wow
the car feels a whole lot more stable, opposed to the stock springs, which encouraged more tilt and sway in the turns, but now it feels more planted and solid, I will report any problems... that is if I come across any in a few weeks time.