Some mfgs will have guides as to what cam you need based on compression, intended use, gearing, etc. Some of them are pretty simple...some not (you can make it as complex as you want). I would look at some of these and see what specs they are offering based on the requirements. It might be good to look at the engine's original cam spec as a starting point. Of course you can sift through YT videos and try to find the good ones.
Here is an example:
https://www.hughesengines.com/TechArticles/2choosingacam.php