Leaf spring differences for 68 C-bodies and maybe other years. Soft to Firm.

Great find on that book I'd seen one at the dealer where i was parts then service manager
I owned 59.65 66 Imperial 69 Polara and 73 New yorkers, one with factory trailer tow
I added a leaf to all of them and had a wide variety of samples to choose from when building a new stack using only the main leaf. I like the plastic interliner it comes in a roll and is full width and cut to length
it has fins up and down on each side, slides real nice I spray the leaves with zinc dichromate paint then moly spray'
on the C bodies I install the rear sway from a Cordoba it is a bolt in
and use the 74-78 1" plus torsion bars PC or SW if you can find them PC wheels for a stock or 8" wide
radial tires do not like narrow rims hd quick ratio firm feel box if you can find one or build one
I also built a late 73? B Body ish fury 3 seat station wagon really big torsion bars for these 400 car
Had a 62 Fury 2 door wagon 3 speed 318 poly but had all the matching year 413 parts and a torque tube 4 speed car got stolen, would have made a great show car still have the long rear impossible to find side glass if anyone needs and maybe a spare windshield
 
That’s what I am hoping to draw out from the crowd.
I do know my Polara D-L w 383 engine would have had the 3004 658, but the pn on the bottom spring is 2835 354. Mine has 5-1/2 leafs. So at some time the part number was super seceded.

View attachment 691676
Not necessarily. The part number you find in the parts catalogue is the SERVICE part number. The part number that is stamped on the spring itself is the PRODUCTION part number, either for the entire leaf spring assembly, or for the individual spring itself. Service part numbers and Production part numbers are RARELY the same. Do you recall GM advertising "Computer Selected Springs"? Well, Chrysler to a certain extent did the same thing. Springs varied based on what optional equipment is built into a car. I recently saw a sheet on a car that looked like the window sticker, but it had notations with the individual options of how much they added to the weight of the car. Not sure where or why sheets like this would be printed out, but there are engineering books that list all this information.

IF you're looking to make a reasonable improvement in the ride/handling of your car, go to the torsion bars and leaf springs that are specified for a 440 equipped car. They will be
larger/beefier than those for a 318 car. Chrysler engineered the cars to ride level, in most cases, with just a driver on board. If you want your car to ride level with all seats occupied and the trunk full, consider air shocks and a height control valve. '78 NYBs among others had a vacuum powered pump that could add air to the rear shocks when called for by the height control valve. There are aftermarket kits that can do all of this, with a small electric compressor.
 
Back
Top