I don't know about many other places but ill take a 307 any day and twice on sunday. so its not a 350, so what, why is it the common practice is if you don't know throw a 350 in it. why not 283 or 400 be original.
start small work your way up.
for you cam, you'll have about a 800 rpm difference than advertised, so look at your application then go from there