John and Troy,
When you have to compress the springs just to get them on you are preloading them and then any additional adjustment to get the car level or the corner weights correct adds additional preload. When preload gets to large it makes the suspension very stiff until the preload is over come by the load which normally would very small on a Bonneville car assuming a smooth course. This can make the car feel like the springs are to stiff and if the preload is large enough you will get no suspension travel. I would think that the springs you have are to long, my preference has always been that when you jack up the car the spring will become loose on the shock and not preloaded.
Just a thought.
Rex
Rex...We had to compress the spring to clear the lip on the spring retainer and get below the lock nut on shaft for top mount.
Retainer slot is only wide enough to clear shaft but is machined to clear nut and center on top mount. Once spring retainer is in place there is no pressure on spring and bottom spring pad can be turned by hand.
Alston must be on the edge of overall length for these rear shocks for them to work for there chassis [ there book specifies a certain length] to come out at the correct ride height.
The fronts were a longer shock and we had no problem with 12'' spring on them and like you say are loose when jacked up
and gives us room to lower or raise the front end.
JL222