The "hemi tick" surely has several possible causes, but aside from trying different oils or additives, changing out the pushrods (and the rockers if there's evidence of tip wear) is probably one of the easier things to try. I think the stock pushrods are just poorly sized and straightened from the manufacturer, and can cause at least some slop in the valvetrain.

OK so I was a bit bored today and took some measurements of the stock pushrods from my engine and compared them to a set of aftermarket rods. The aftermarket rods are a three-piece version and are probably good, but I'll be sending them back for a set of one-piece rods that are advertised to be straight to within 0.001", length to spec within 0.002". Full OCD.

Tip diameter - Didn't bother to plot these, because they were all right at 0.312" (5/16") for both stock and aftermarket.

I refuse to spend around $100 for a pushrod straightness checker stand, so for the total indicated runout, I placed the pushrod ends (with a bit of assembly lube) into two of my old rockers, and clamped the rockers to a workbench. Digital indicator was resting on the workbench. The 1" digital indicator is a Harbor Freight POS, supposedly good to +/- 0.001". It took some patience and finessing with this setup, but I was able to get a repeatable set of measurements. The values shown on the plot are the maximum of three for each rod (one measurement taken at the center and about 1" from each end).

Lengths were measured with an Insize brand dial caliper, 0-12", accuracy +/- 0.001".