What is the difference between the springs on a 72 down pickup compared to a 73 and up? Length?????

Helps if I state which springs....Front.

My guess would be compression rate, or how stiff it is. I dunno though. Like i said, my guess.

the 73+ springs are a little longer, all you need to do is make new longger shackles

the 73+ springs are a little longer, all you need to do is make new longger shackles

Thats what I thought. Thanxs!