I figured I'd necro this thread since, well, it IS my thread.
Back in 2011, I ended up going with the AC Delco 45H2044 springs and Airlift 1000s.
https://www.rockauto.com/en/moreinfo.php?pk=440508&jsn=3
The Airlifts eventually stopped holding air, which I traced to the hoses getting slightly cut where they rubbed as they went through the top spring mount. I replaced the hoses and all was well for a thousand miles or so, and the springs no longer hold air again. (I originally wasn't diligent about maintaining at least 5 PSI in them, but after going through the trouble to replace the hoses, I made sure at least 7-8 PSI were present.)
The main reason I use the Airlifts is that I periodically tow a trailer. Usually it's a beefy 5x8 utility trailer (full-sized 15" wheels, strong frame) hauling a couple of motorcycles. Without the Airlifts, the back of my wagon will drop at least several inches, so they are necessary evils.
Thing is, the diameter of the 45H2044 springs is so wide that it's a pain to get them completely out of the car--I can get them off of their perches, but I have to raise the opposite side of the rear axle to get the other side to drop enough where I might be able to wiggle out the spring, maybe. So, I am not really looking forward to messing with the Airlifts any more and have started researching alternatives. My goal is to run a spring that is stiff enough to not need the Airlifts when pulling a trailer.
I found this thread, which talked about using the Moog CC623s or CC625s.
http://www.impalassforum.com/vBulle...ock-combo-wagon-ss-springs-2.html#post2722487 I also found this Moog spring chart.
Universal Coil Spring Specifications | Moog Suspension Parts
The spring specs are as follows:
45H2044 installed height - 8.5" , constant spring rate
CC623s installed height - 11" , variable spring rate of 206 lb/in.
CC625s installed height - 10" , variable spring rate of 222 lb/in.
Since the 625s sit closer to the 45H2044's installed height AND have a higher spring rate, those seem like the springs to go with. Thing is, I don't know what spring rate the 45H2044s are and haven't had any luck with Google. I figured that the coil diameter might tell, with thicker coils being stiffer, but the 623 has a thicker coil than the 625, but is a lower spring rate, so that assumption isn't correct. I'd hate to go through the trouble of swapping out springs only to find that the CC625s aren't significantly stiffer.
You guys think the CC625s will be stiff enough to not need the Airlifts when towing my motorcycle-laden utility trailer?