OK, I almost figured that, but doesn't hurt to ask...you know full well there are some folks on here who try to build a race engine on a shoestring budget and then are crestfallen when the reality strikes and can barely rebuild or freshen up what they're working on.
I would think that a good off the shelf cam would work just fine for you if you're using stock valvetrain components, and 350-375+ hp won't be difficult even if you're staying with your stock sized valves, and even if I'm a bit put off by the way yellow rose presents his rationale and discussion, he's correct with the math. There are much better things to be done with the seats and valves and how you actuate them with the cam. I also know he gives zero f!@#$ about what any of us thinks, so there ya have it. :)
I think of the things I've read when it comes to aftermarket, you're still going to spend a pretty penny because according to the bright people on here, (IQ, moper, et al) you shouldn't run aftermarket heads OOTB-they should always be double checked for proper installed height and valve job at the very least and that adds cost to an already potentially large expenditure. X or J heads will get your goal-no problem. Prep them correctly with a good valve job, maybe some bowl work if you can swing it, and a properly chosen cam and you'll have a SWEET running 340 that won't kill your bank account, won't be temperamental, won't require race gas, and will be reliable.[/QUO
Dayum you guys are brutal on old YR.
To the OP....since you are taking your time, and you are thinking about what you are doing, I suggest you seriously consider an adjustable valve train. Even if you find a used set of 273 rockers. And a solid lifter cam. If you have your poop in a group, geometry wise, you should have to set the valves maybe every 5k, maybe even less. Then, you can do some relatively inexpensive oil system mods THAT WORK. Go to B3 racing engines web site and read his tech stuff on geometry. Money spent on valve train is money well spent. And a solid lifter will make more power, everywhere over a hydraulic. The only reason the factory went HFT was cost. Way cheaper to stamp a rocker than cast or forge one and machine it.
A little time spent now, with a pencil and paper will save you money and time in the long run. And make your finished product end up closer to your expectations.