That sounds like an Isky grind. If it is, the springs to use are as follows:
Dual with damper, chrome silicon
Visual i.d. blue-orange/yellow
O.D. 1.005"/1.430"
I.D. 0.730"/1.070"
Seat pressure:
135# @ 1.750"
285# @ 1.200"
Rate per inch: 275#
Coil bind: 1.120"
Max net lift: 0.550"

How's that for an answer?????