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...

That cam is not really a street friendly cam based on that lift and duration. Street driving something like that is going to wear out ANY spring on the market quickly.
If it was mine, with that much cam I'd only run a PAC spring and give them all the info on the cam, rpm range, etc....I'm thinking seat pressure should be closer to 300lbs. and open is about right. Also, what lash are you using?