Broken rocker arms two weekends in a row

I run PAC 1355 springs on the intake valves. New intake springs are installed @2.100" and have 450# spring pressure at that installed height. 780# spring rate and 1.130" coil bind. 1200# @ 1.175". They lose roughly 50# after break in. The collapsed spring has 295# at that installed height. The exhaust springs have a slightly different rate as the exhaust valves are lighter and don't have as much lift. You're welcome to come over with your own spring tester and compare it to the 2 that I use.