Need advice on 2008 CRF450 engine mods

I had an 05, 06, and 07. Here is what I liked:
Stage 2's for more over-rev, spend the money on good Ti valves, run a high comp CP piston, keep the stock header and buy a Yosh or FMF slip on. Get a fuel screw and Rev up to and into the Rev limiter in 2nd or 3rd on the track and play with the fuel levels. Take the backfire screen out if there is one still in the filter cage, run 110 (cheap sunoco does the trick)

You could also send your black box to Tokyo Mods

Start with a high compression piston, U4.4 with a good carb tune, and full exhaust system. I think you'll be surprised how much that changes the power spread.

If you need even more.... a new cam (I like pro circuit for this model) matched up with some port work by a reputable builder.

I had a 2007. Same engine. The 13.5 piston makes a really nice improvement in the low to mid pull. Bike still ran great on 91 pump fuel. If you need more over-rev you are a serious revver or ride really long wide open tracks. I always though the bike had plenty of over-rev. Could hold 3rd pretty long on some straights.

The 2008 has a gear position sensor that retards the ignition timing in 1st and 2nd gear to soften the power and lessen wheel spin. Many people disconnect it to get the 2007 snap back.

Wiring the accel pump on a 2008 CRF450 doesn't make sense because the 2007-2008 CRF450 essentially already have that done stock. Grinding the rivet on the diaphragm down also doesn't make sense because the carb has a zero-height rivet. The carb is different than the Keihin FCR on every other 4-stroke MX bike. Those mods actually sound like what you would do to a 2006 carb to essentially copy the 2007-2008 carb.

Carb info: http://www.thumpertalk.com/topic/338687-2007-crf450r-carburetor-updates/

Best motor mod I did to my 08 was head porting. The guy that ported it told me the intake port design of the 08 was one of the worst he had seen on any Honda. Took quite a bit of material out in order to straighten the flow to the valves.

13.5 with a hot cams stage 3, play with gearing it will rip.