67 283 keeps bending pushrod

[brantbain]

fellas,
I have a 67 283 and cylinder 7 the intake valve rocker slips off and bends the pushrod.
I installed a new lifter/pushrod then put the original rocker back on and when adjusting it if I barely tightened it it would want to slip off. I changed out another rocker and the same thing happened.
I tightened it just enough to take the tick away and took it for about a 15 mile spin, about 10 miles in I gave it a good shot and bam I got the lifter tick, came home pulled the cover and found the rocker off the valve with a bent pushrod.
The post on the head doesn’t seam bent
Any ideas?

Cheers
Brant