When I first got the car, it still had the original style (maybe original?) springs, which seemed to be tired, along with the rest of the suspension. I tossed those springs, but probably should have kept them for reference. They were replaced with standard height but stiffer springs, the rationale being we were big dudes and stiffer springs might help keep the ride reasonable. I had also read about the acceleration squat of original rear springs and wanted to avoid that.
Lately I've been feeling like the car is standing a bit tall, and especially with the Waumandee hill climb coming up I decided to try a new set of springs to improve the car's cornering.
Because they're cheap and ship fast, I went with these 1" lowering springs from BP Northwest. They're rated at 400# front and rear both, which is different from the original setup of 305# front, 350# rear. Other uprated springs have different rates, and maybe that's a better way to go, but I figured these would be close to the spring rate I had, just a bit lower, which seems like a safe bet. It's also close to what others use for their uprated springs (Good Parts version is 390/470).
I did the rears first and was really happy that I had previously installed the adjustable swing arm brackets because the camber went from about 0 to -3°. I was able to adjust that back to neutral spec, and the brackets are still well within the range of adjustment.
The fronts were a real mess at first. I took the trunnion apart while removing the old spring and had a terrible time getting the new spring back and everything lined up. I actually gave up on the conversion because of the short time before the hill climb, but after sleeping on it I realized I was way over-complicating the process.
For future reference, get the front end up pretty high for plenty of working space below, DON'T undo the trunnion, just unbolt the pan and lower it with the spring compressor. The spring compressor along with the floor jack helped compress it back into place to re-bolt the lower pan. Much easier and quicker. The front wheels measured at about the same camber after, so I didn't make any adjustments to the a-arm shims.
The first attempt with new springs and standard pads was too low; I got tire rubbing in the rear on moderate bumps with 2 people in the car, and even on hard acceleration. In the front I actually took a few slices off the corner of one tire while backing out of a driveway at an angle. I added a 1/2" spacer in the rear and thicker poly pads in the front, and it seems to be more usable now.
Measurements, floor to fender arch:
Ground clearance before was about 6" before at the lowest points at the front frame, 7.25" for the lowest point on the muffler. After, it's 5.5" at the front, and 5.5 for the muffler at the rear.
I'm not sure whether I’ll keep this setup for normal daily driving use. I think having it this low would be totally fine with stock wheels and narrower (original 185 size) tires, but with 205 width tires on 16x7 rims borders on overfilling the wheel wells. It looks great, but if the tradeoff is having to drive it more carefully all the time it may not be worth it. I’ll give it a few weeks of driving to decide.