I had 440 source 1.6 rockers on dads motor, solid cam ran to 6500rpm, brad penn 20-50 oil, 155 on seat 380lb open. Had a couple hundred street miles and a few passes at the track. Upon Tare down to change a few things I found the roller bearings started to gouge into the shafts.
Changed to a .680 solid roller and Hughes rockers. Maybe csk had better luck than us but on a mild cam they would probably be fine, I’ll never use them again though. I’d rather use ductile rockers as I’ve beat a set of those to death and they are still perfect.

If you do use them check the clearance of underside of the rocker as they made contact on the 1.55 diameter retainers so slight grinding was needed