As mentioned, with a mild cam like this, you really only need to have the correct lifter pre-load, which can vary quite a bit with stock type lifters, from about 0.020" to 0.080" (some lifters can take a bit more depends on brand.) Usually, I like to get custom length pushrods that give 0.040" lifter pre-load.

Here is what I use when deciding to not use the stock rocker arms:
Higher valve spring pressures can push the pushrods through the stock rocker arms. So, when going over 0.500" lift with stiff valve springs, it is a "good idea" to upgrade the rocker arms. I quoted "good idea" because everyone is going to post their 292/0.509" cam works fine with stock rocker arms. Alot depends on the valve springs used (seat pressure and spring rate), and how aggressive the cam lobe profile is.