Reading threw this thread in gotta say you guys really know your stuff, and I'm have to really think to follow along so thanks for helping the learning curve. What I can add not sure if it helps but the 273 I pulled out of my 64 had a stock 340 cam installed by my dad in the 80's I don't know what particular 340 cam but I do know that thing idled like it was a huge cam and power was way up in the rpm band.
Oh you can put a big cam in one and it will have power but it won't have very good street manners. Many car guys overbuild/over cam their engines and then are disappointed when it isn't fun to drive unless you wing it 6000 rpm.