I have a 99 WR400
I'm in the process of rebuilding it and boring it to 426cc with a 13.5:1 piston and some mild head porting and 2003 style auto decompress cam.
The bike engine wise will basically be a healthy yz426.
I was looking to get away from the old style carb with all the octopus junk hanging off of it and upgrading to a newer yz carb.
Im sure there are plenty of you guys out there who have done this, so just wondering what you all think the best bet would be as far as what to go with.