Drop coil interchangeability? What fits?

[OKGMC4]

My 56 has been done for a year now and I'm bored so I am starting a 69 I got for free. My approach is somewhat strange on the front. I am using 73-87 control arms and drop spindles on the 69 k member, and I am adapting a dodge dakota rack and pinion to the frame for steering.

The question is this...why aren't the drop springs on 73-87 trucks the same part number as 69-72? The spring pockets all look the same and the K members are nearly identical. Not sure which ones to order?

[lolife99]

67-72 and 73-87 front springs will interchange.

[OKGMC4]

Thanks. That's what I suspected. Just strange that all aftermarket springs say either 67-72 or 73-87 but not both.

[lolife99]

Originally Posted by OKGMC4

Thanks. That's what I suspected. Just strange that all aftermarket springs say either 67-72 or 73-87 but not both.

Where are you looking?

[OKGMC4]

JEGS, Summit, ECE, LMC. The part numbers differ. I used the Federal Mogul website and they are different there too. I don't doubt they fit but a slight change in spring rate or free height makes it a different part number. A long time ago I put third gen firebird springs in a second gen TA to get a 1.5 drop in the front. A ton of GM stuff will change out if a person only knows where to look.