rocker arm advice

Stock rockers can be a bit of an unknown. I had stock rockers in a car that would run high 11s but still had the occasional failure (shoved a pushrod through the rocker). I was using a Crane 520 lift cam and the engine would see over 6000 rpm a lot. My old 70 Chrysler Town & Country had an HP 383 engine that ran like a striped a$$ ape but made a lot of valve train noise. There seems to be some variables in the thickness of materials used. Combine that with wear and you can get pretty noisy. If you scrounge through a few sets of BB Mopar rockers you will find some that are really loose on the shaft and some with a much better fit. The ones with the less elongated shaft hole are usually thicker or formed better all the way around. For most street applications a good set of OEM rockers that have been culled and assembled properly will work just fine. As mentioned above if you have light or no preload they will make noise and tend to fail.