Mustang ll coil over spring rate

[Hampshire]

What do you have for a spring rate? I have iron head SBC with springs rated at 500#. The shocks are Viking A201 (similar to the A203).

Without going into a long winded explanation, we're doing a little readjustment this coming spring & I'm re-evaluating what I have. Ride is firm but very nice. Hitting a bump on the highway at 70mph is tolerable, but it wouldn't hurt to be a little better. Anyway, I have the opportunity to first change things up front: longer travel on the shocks & maybe swap in a lighter (375#) spring.