broken valve springs

on my 580" with 572-13 heads, all of my inner springs broke. some into 3-4 pieces. i have the jessel set up. i only have about 500 miles on them as this is a street car.

the springs i use now are k motion 1000h,s. is there a better spring? i have heard that the k motion springs would break eventually. it is a solid roller with 1.7 rockers. the cam specs:
.800"/.750" 282/290 @.050.

the k motion 1000h specs:
1.625"
265# @2.00"
790# @1.250"

i would need something close to the same specs. i will be changing them with the heads still on. this is a street car, so reliabilty is the main concern. thanks...