For What Its Worth
Front Springs
My 66 had a 6 and now has a V8-283. Looks like original springs. Bushings are tight, but time etc. has caused the front to drop about 1.5" from stock height. The back is at stock height, but only after using shackle extensions. Everyone likes the looks, but it doesn't handle well in corners. The front rides heavy and I want to correct this with new springs when I redo with poly bushings etc.
Heavier springs will not eliminate the roll, but stiffen overall ride. Too heavy and the spring action is gone.
New springs at the stock rates are usually what is needed when dealing with 10-40 year old stock springs. Coil springs will loose their tension when used for many years and 100,000+ miles. Normally they fade together and it is a slow process so most people don't notice. The mono leaf rears are notorious for sag/fade.
Sway bars are better at stopping roll while maintaining the ride going straight. If you want less roll, get a stiffer/bigger sway bar. Some roll isn't bad. It helps transfer weight to the drive wheel that needs it in a turn.
Suspension setup depends on what you are doing, street or drag. I like street/circle track setups.
Front springs install
When I took out my stock front springs for replacement the ends of the top and bottoms of the springs were exactly 180 degrees apart. Everything was fitting like the factory manual said it should.The replacement springs I got were about 170 degrees apart. These were supposedly the best of the best. I aligned them to the stop on the lower spring mount, an 1/8th inch from the stop.
On the upper spring mount I bent the tab down that clocks/aligns the upper mount. I put the upper mount in the car clocked as they needed to be for the new springs. Then in the hole in upper fender well where the old index tab had gone, I used a small, self tapping screw and screwed into the upper mount to hold the clock/alignment of the upper mount. Make sure the upper spring mount is centered when you put the bolt in. The bolt should not touch or scratch the spring. I put the car back together. The springs didn't move, all is OK.
Lower spring mounts. Mine were still good and tight. I cleaned them up and made sure the rubber boots were on correctly. If someone gets carried away with a grease gun it pops the boots off the ends.
One last note. The shock towers are not symmetrical, almost but not quite. The "manufacturers mark" stamped on the tower goes outboard, towards the outside of the car when you put it back together. The mark varied over the years and not all the same supplier. Here is a picture of mine, with the mark circled in yellow.
Once I replaced the front springs, it was time to replace the rear. Rear Spring replacement notes.
