I have my opinion on this but it is always insightfull to hear other peoples reasons and what is there deciding factors .

-beerjet-

I dont know that Joe Schmoe who's rebuilding or building a mild lake rod wants to spend all that money . Believe me , it's ideal .

-beerjet-

I have used the same method for years, find a camshaft that is advertised to run at or very near the engine RPM that you need to be running to make your combo work, using information like; intake runner length and overall size, carb CFM and type, cylinder head port and valve size, exhaust type, CR, limitations of exhaust pulse (use a 112* lobe center to minimize) and so on.. it all needs to work together, otherwise the wrong choice is inevitable.

A lot of the time, a cam manufacturer will make a proven camshaft for certain application, (like circle track, jetboat, drag, etc.) sometimes they are the inexpensive way to go...

I have a "recipe" that I follow, but it's considered top secret 

GT