/\ What he said. As long as you're not running oversize valves, you shouldn't have clearance issues. As for the internals, 9 times out of 10 the stock block will split before breaking any of the internals. The internals may break as a result of the block breaking, but that's usually the first to go. It usually happens close to 500rwhp, but I've seen them break under 400, and I've seen them hold up over 600. I say keep it in the low 400s with a good tune and don't spin it to the moon.
Edit: That last sentence rhymed, and it wasn't even on purpose. I'ma be the next fifty cents.
I have a stock motor with e cam and 1.7 with no problem and i have busted a stock block with same set up how ever i never broke a rod or crank so they must hold up well