Well, the b16 has a R/S of 1.74. That is better than all the other leading engines, but you really do have to upgrade the engine a whole lot more than just what your talking about. If your reving that high, your going to be making a LOT more heat... so at that point its not about breaking your engine, its about warping it. I would think you would need forged pistons and stronger cylinder walls at the least.
You have to really think about the R/S Hype thats going on all the time. If you think about it, there is no perfect R/S because your rod will be pushing your piston into your walls in each and every stroke except at the top and bottom of its travel which unfortinately is when your creating no power because the piston isn't moving! It turns around and gets shoved into the wall again and again, except if your reving twice as much, your creating twice as much stress on the engine. Heat will rise and walls will warp.
Now I'm sure you can rev high safely, but you do need to fix up your bottom end to handle the additional stress and heat. If I wanted my engine to last, the least I would do is a resleeve with forged pistons, and maybe a little lighter crank.
I would just keep in mind that people that do take real advantage of a high rev limit have short v8's and v12's because they will still have torque to back up all that HP. A 4 cylinder is just not as good at this IMO because people will be passing you up every time because you dont have the power to back it up. Hell, indy cars have 24 cylinders and a really high rev limit and can obviously tear anyone a new one.
Also, keep in mind:
Profesional drag racers that have a really high powerband don't measure how long their engine lasts in miles... they measure in minutes.