I wanted to post this so ya'll might benefit from my experience. I used 5" CPP drop springs on my '65 C10 SWB Stepside. The ride was like a big ole Buick and the springs were so light weight that hauling anything of significant weight in my truck wasn't possible.

So I replaced the rear springs with CPP 4" drop Heavy Duty Springs. Much better ride and since they are heavy duty I can now haul more than just a couple hundred pounds of stuff :D The new springs look very similar to the OEM springs that were originally on the truck, just a couple less coils and shorter overall height.

http://i645.photobucket.com/albums/uu176/lakeroadster/1965%20Chevrolet%20C10%20Pickup/Engine%20and%20Driveline/Rear%20Coil%20Springs/GEDC0496_zps3a73eb16.jpg (http://s645.photobucket.com/user/lakeroadster/media/1965%20Chevrolet%20C10%20Pickup/Engine%20and%20Driveline/Rear%20Coil%20Springs/GEDC0496_zps3a73eb16.jpg.html)
4" Heavy Duty Drop Springs are on the left, CPP P/N 603-4HD, 5" Drop Springs are on the right, CPP P/N 603-5

http://i645.photobucket.com/albums/uu176/lakeroadster/1965%20Chevrolet%20C10%20Pickup/1%20Current%20Status%20Photos/GEDC0539_zps8f34943c.jpg (http://s645.photobucket.com/user/lakeroadster/media/1965%20Chevrolet%20C10%20Pickup/1%20Current%20Status%20Photos/GEDC0539_zps8f34943c.jpg.html)

Ditto....exactly why I changed during the tank install.....don`t care to drive a 54 buick....anim_63

Thanks for the info.

Lake, can I use the CPP 4" HD drop springs without a notch? (`65 stepside)

Correct Donnie....! truck bed shown with 4 inch drop HD springs, you will need shock relocatonin the rear and an adjustable track bar.

Lake, can I use the CPP 4" HD drop springs without a notch? (`65 stepside)

Donnie,

I didn't need an adjustable panhard bar or a notch and the rear axle is centered. Here's my how to on shock relocators: http://talk.classicparts.com/showthread.php?p=88325#/

Donnie,

I didn't need an adjustable panhard bar or a notch and the rear axle is centered. Here's my how to on shock relocators: http://talk.classicparts.com/showthread.php?p=88325#/

There has been a lot of variances on those that had to install adj track bars and those thst didn`t, so its really amounts to after drop owner needs to measure differance from side to side wheel to fender tolerances sense beds are not adjustable to frame ( maybe .5 inch ) over on the darkside they thought maybe it was by year but still made no sense.

There has been a lot of variances on those that had to install adj track bars and those thst didn`t, so its really amounts to after drop owner needs to measure differance from side to side wheel to fender tolerances sense beds are not adjustable to frame ( maybe .5 inch ) over on the darkside they thought maybe it was by year but still made no sense.

Sloppy manufacturing tolerances and 50 years of "actual truck usage" will definitely result in non-consistent results, one truck vs. another. Worn out bushings also account for variances.