[Karch]

Originally Posted by Shadowjack

'67-back are tangential on both ends. '68-up are tangential on one end, ground flat on the other.
SJ

Thanks for the clarification...I knew there was a change around that time.

[Ken K]

68 and up front replacement springs are not ground flat on top like the factory springs. The replacement springs are like the 67 and earlier springs on top. I use a 68 and latter spring in a earlier car because there is more selection and you can get higher spring rates without buying aftermarket springs.... The back springs are different. The 67 and up use a pig tail on both ends, the 66 and earler use a pig tail on the bottom only.