I called Air Ride and spoke to a very helpful guy. I used the C10 rear bolt-on kit on my '65 C20 and the installation was quite simple. I didn't do front airbags because of funds so instead I modified my lower control arms by cutting out the coil spring pocket and welding a new one in that's lower. Cut just a tiny bit off the coils, not much. There's still close to a full spring there. Doing that got me about a 4" drop in front.
Things that you need to do for the rear (stuff I didn't really know about and had to ask during the project):
-Relocate shock mounts. Just installing the bags will lower your truck significantly even with 45 psi (about where you want to be for driving with empty bed) in them so, your shocks now become much less effective 'cause of the angle. I did mine like this. [img]http://img325.imageshack.us/img325/4263/dsc001175yo.th.jpg[/img]
-Buy or make adjustable panhard bar. At your new ride height, the stock panhard bar will kick your rear axle over causing it to be uncentered. With an adjustable, you can get it back to center. Not sure what the C10 panhard looks like but with mine, I hacked off one end and welded some 3/4" threaded rod on to the eye. Then welded a coupling onto the bar. I got both the rod and coupling for cheap at Holmes Depot. Looks like this: [img]http://img312.imageshack.us/img312/7724/panhardbar8rj.th.jpg[/img]
You can buy everything you need for front and rear from Classic Performance .
Since I've got a C20, I can only lower the rear so the frame is just about touching the axle. This is because of the huge pumpkin on the 3/4 and 1 ton trucks. With frame just about on axle, the pumpkin is touching the bed wood. I'd have to modify bed to go lower. With a C10, you could probably go lower so you might think about doing a C notch kit to go lower and for more travel.
Wish I could tell ya more about the front but this is the best I can do.
Hope it helps.
If you'd like to see pictures and text of how I did my front lowering, check out the "Files" here: Kustoms-and-Sleds
The way Yahoo has it setup, you have to join the group (it's my group) to be able to view files and stuff. Then after viewing, unjoining is just as easy as joining.
-David


Tradin' up dimes for nickels...
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My \'65 Chevy C-20