Y-Block rockers
 

I have a 57 with a 312 that has two types of rocker adjusters, some are the threaded adjuster with a lock nut and the others are hollow that are supposed to have an interference thread. Some of the latter can be turned with my fingers so they won't stay adjusted. There is not enough thread showing to use a jam nut, not even a thin one. I considered using a sharp chisel to interrupt the threads or cleaning squeaky clean and using a drop of blue Loc-Tite to lock into place. Any suggestions will be appreciated or maybe new rockers is the only solution. Thank you.

Re: Y-Block rockers
 

Just saw that this has been answered in a previous post but thank you anyway.

Re: Y-Block rockers
 

Check also that they are the same ratio, I had a high ratio (1.54) and low ratio (1.43) rocker on my 57 when I purchased it and it always ran funky and could never get rid of the pinking with timing adjustment, I fitted another high ratio rocker and it ran a lot better and timed up without pinking.

Anyway the high ratio had the interference nuts 1/2 head (i think) and the low ratio were 7/16 head adjusters. I have also seen the slotted screw type with jamnuts but only in low ratio rockers.