[Chambers]

I would say you need all new connecting rods and pistons for the bottom end, the stock connecting rods may give out at higher rpms.

As for the valvetrain, you would need stronger valvesprings so they will adquetly close so they do not hit the pistons, then you would problably need to replace all the other valvetrain componetns as well.

I did read somewhere, that there was someone who would take Toyota ECUs and "tune" them for a higher rev limit and fuel maps, but you can do that with a piggback ECU as well.

You would have to lay down some serious cash to do this, but in the end you would have one reving mo-fo.