I’m kinda at a loss here guys ls3 crate long block, btr stage 4 cam, stock heads milled .030, stock head gaskets, ls3 rockers with trunion upgrade by Michigan motor sports, c5r timing chain, Johnson 2116 lifters, mahnton pushrods measured to correct length with added preload, stock intake. Made 506 wheel hp and ran like a beast for about 500 miles and now this rocker snapped and all the intake rockers have an indentation on the tips. Pistons were flycut and had 0.085” of ptvc and I don’t spin the engine over 66-6700.
Help

Yeah, somethings not right there. Judging by the fact that the indentation is centered on the pad, it looks like the geometry is probably okay.
What do you mean by pushrods measured to correct length “with added preload”? IIRC, Johnson recommends .035” preload for those lifters? I’m assuming that the trunnions are okay and not binding and they were all installed correctly with the round part sitting in the rocker alignment bracket? I don’t think any of that is the issue though. It takes some serious mechanical interference to snap one of those rockers off like that, IMV.
I would bet that the intake valves are striking the piston and that’s what's causing that problem. I know you said that the pistons were flycut and it had 0.085” PTV clearance, but I would follow the advice already given and pull the heads to check to see that the intake valves aren’t somehow hitting the piston.
Hope you solve it man, sounds like a nice combo you have there otherwise.

Well, if they are in fact weak castings due to poor metallurgy, that would actually explain everything: The indentations on the rocker tips would be caused by the inferior/softer metal being worn away by the valve stem due to the heavy pressure of those double springs, and the end of the rocker snapping off would also be an obvious symptom. The damage to the retainer is obviously caused by the sharp edges of the shattered rocker bearing down on the retainer, rather than on the valve stem. The valve stems and locks look undamaged to me.
I had no idea that there was such a things as a Chinese made LS3 rocker. Sucks that you pay for an “upgrade” and get **** quality like that. That’s why folks should only buy parts from reputable vendors like BTR, imho. From my own experience, Tooley is one of the most honest, decent and helpful vendors I’ve ever dealt with. I would strongly advise you to give them a call and get yourself a new set of genuine factory rockers with his trunnions installed and a new retainer to replace the damaged one. Then change your oil and hope that there are no shards of metal left hanging around from that shattered rocker.

Fair points.

I still feel like those stems are sitting lower in the keepers than they should, but maybe my eyes are playing tricks on me. I wouldn't feel confident unless those heads came off and were disassembled.