How strokers affect how a cam "acts"

Engines Strokers increase the displacement of an engine which in turn makes the cam act smaller. Generally if you pick a cam 2 sizes larger than the characterisitcs you are looking for, it wil be a good choice. If you are confused...please call us.
This is a quote from hughes camshaft recommendation.
now the high rpm comment is because it will be used in the mud as well as "street" racing more so on the open roads around here. For some reason in my area it is commonplace to race trucks more than cars. and most the trucks out here are roller cam 383 strokers from the 67-72 area.