I am having trouble with my stock rockers.

To give you a little information about what I have:
This is an '04 5.7L punched out to a 392.
It has Thitek heads with 2.165 intake, 1.65 exhaust, dual springs; PSI 1512s.
Comp Cam with gross valve lift, intake: .636, exhaust: .620.
Comp Cam hydraulic lifters: 15820-16.

Everything has about 50 1/4-mile passes on it, except the stock rockers. I did not see a problem with them, so I ran them.

My problem is, after inspecting the rockers and valve stems I noticed that some of the intake valves only (1 intake valve on the right bank, and 3 intake valves on the left bank) were mushrooming at the top and obviously the rockers were showing damage as well. The exhaust valves were unaffected. I do not see any bluing or other signs of oil starvation. According to my engine builder, the pushrod lengths were checked with zero lash, plus 20k. After talking to Comp Cams, that is correct for this particular lifter. The pushrod lengths were 6.920 and 8.240.

I have not removed the heads yet to replace the intake valves, so any thoughts you may have would be appreciated. I have also considered installing lash caps, what are your thoughts on adding those?

Thanks,

PS This is the same combo as Triple Threat except the heads.