<VV> ? Rocker Failure - Twice! ??

[Kent Goddard]

Looking for help! 
Recently had my '66 140 rebuilt. Blew out #1 intake rocker arm at 500
miles (see photos).  Today at 600 miles
blew out #3 intake rocker in exact same fashion.  Appear to be overheated as both are somewhat
gunmetal blue.  #3 exhaust has not failed
but appears blue.  Others on R bank look
OK.

 

A few other facts: New Clarks mated grooved ball repo
rockers, new Clarks deep dimple lifters, reused pushrods (oil passages fully
open), 270 cam, new PEP springs with 105# seating force (not 'bottoming out' at
full lift), reworked heads (deep seats, milled to remove all but .010" of
land, mag bronze valve guides, etc.). 
Brad Penn 30W break-in oil for 600 miles.  Just put in Brad Penn 10W-30 today.  No loud tappet noises.  Not over-rev'ed.

 

I planned to drive the car to Knoxville next week but am now
having serious doubts.  

 

Has anyone seen or heard of anything like this before???

 

Many thanks.