I've run Comp, Lunati, crane, Erson, isky.... they are all pretty much the same IMHO. Find a grind that would work and run it. For this type of build, you could run a Lunati 60402 or 60403... another good camshaft. You may have to machine the guide to insure no interference when increasing lift. Just a requirement to play the game.
One place I would spend a few extra dollars is to get the 273 adjustable rocker arms and decent pushrods. That decision opens up more potential cam choices.
I've run a 274 with stock rockers and it's right on the edge. Stock style rockers don't like more than ~300# open pressure. As moper noted, once you get past that point, they start to pop apart. The nice thing about the 268 is that it use a simple single spring/damper set up and not a double spring. Thus no machining required to the head for the springs.
You can find 273 rockers for as little as $50/set. I've seen sets advertised here for that price.
The build Haney mentioned should get you close to mid 12's. The westech dyno is a bit happy on numbers compared to others that were just about spot on for weight/mph computations. Build that engine and slap a Holley instead of the ede carb and you'd be in the 400hp range. Enough to go 12's.
I had trouble with Haney's link. Try this and go to the very bottom of the mopar section "340 Dyno derby"
http://compcams.com/Community/Articles/
