Helping assemble a friend's road race 340 with EDDY aluminum heads, and using Hughes rocker 1.6 arms and their valvetrain hold-downs that uses studs. We kept experiencing the studs would unload (despite being tightened into the head very securely, in our opinion) and turn out of the heads. Can anyone suggest a better hold-down method than the studs? Factory bolts? The Hughes complete valvetrain setup appears to be top quality, however, the studs could be longer so to allow grabbing the cap nut, as you first have to progressively work down the shaft without the shaft retainer because it's fairly thick... and then progressively change to the retainer with the washer and nut when there's finally enough threading to grab.

This same engine recently had one shaft snap/break due to the studs coming loose (we'believe that's what happened).

Any suggestions would be appreciated. (Hughes is being contacted also by the engine owner for his suggestions.)

This car will be racing at Road America Vintage weekend, July 20-22... come and see it.. awesome! (and the Posey and Gurney cars will also be racing there that wknd). 1967 B'Cuda fastback #48 (Gurney Blue).