Foreign valve springs in a Magnum

Thanks for replying,

As far as I know, those were the stock OEM bolts for the Mopar Performance P4876050 rocker arm set.

I should clarify, the bolt didn't fail while I was torqueing it down, but rather while trying to adjust the valve lash - which was recommended by both "How to Rebuild your Mopar Magnum V8" and "How to Modify your Mopar Magnum V8" both by Larry Sheppard and published by HPBooks.

Neither specified exactly how to adjust the lash - I had read and heard elsewhere that you tighten down the bolt per the sequence given in the manuals until you cannot turn the pushrod - then another half turn.

Is this incorrect for Magnum engines?