I have messed with the 126 model from the later 80's that have the subframe rusted out where the shocks mount and even then the cars were not down in the rear end...You either have the wrong springs..length or spring rate is wrong...the only solution if you want to keep the springs is to install a new spring cup at the bottom. You can make the spring cans from pipe/tubing.. easy to do...just determine how much higher you want the car to ride and buy 2 pieces of pipe(length needs to be the amount you want to raise the car plus a couple inches longer for the spring to set down in) then weld a piece of 1/4 inch plate inside the pipe with a couple drain holes and then while the car is down apply compression springs and then jack up the body and install the spring cups by welding(disconnect the battery first) the new cups to the existing cups...IT WILL BE MUCH EASIER TO CHANGE THE SPRINGS...PULL ONE OF THE SPRINGS AND HAVE THE SPRING RATE CHECKED...

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James A. Harris