I did have a ticking that developed on my 292 with crane rockers at about 10k miles. The noise came in real slowly so it shouldn't be the problem you are having.
When I had rebuilt the engine the stock pushrods turned out to be a good length and they were all in good shape so I used them. They were the stock one-piece with the rolled ends.
One of the pushrods had broken some pieces loose around the hole and had gouged the steel insert in the rocker. The pushrod end was jumping around in the pocked instead of rotating and swinging smoothly.
I found a guy with a partial set of SBC Crane rockers that used the same steel insert and was able to replace it. The other rockers were still good, but the other pushrods were starting to show roughness around the hole.
I replaced all the pushrods with the style that have the machined ball inserts on the ends.
Three years later and still going good.
