Toyota Repair: Toyota wont wind up, torque curve, peak horsepower

Question
I have a 2001 Tacoma 3.4 v6 24 valve it run good up to about 4200 rpm then it cuts out,like it hits a rev. limiter. The exhaust is not plugged, the fuel filter is new, the spark plugs are new, plug wires are new.

Answer
Fuel cut is around 5400-5800rpm i think. 4200rpm is peak horsepower. It's downhill after that.

http://img.photobucket.com/albums/v414/Toysrme/Data/3vzeVS5vzfe.jpg

http://img.photobucket.com/albums/v414/Toysrme/Data/5vzTRDstock-2.jpg

You sure it's cutting out, or is it just running out of steam? Because those things have a mountian of a torque curve. The cams are just very, very conservative & have absolutely no top end.