What to do with my 400ex

[FoxMxRiders]

I have a 2001 400ex that never been rebuild.

Here the mods :

Uni Filter
Lid off
Yosh slipon
Stadium front shock (fully adjustable)
Air scoop
Killswitch
Renthal
...

But I need more power.Doesn't have the cash to change for a 450R because of my car.

I was thinking about 2 things

Swap the engine for a 2R or Cr250 one that I will build this winter.

Or the build a 426 or 440

Here the mods I was thinking

426 or 440 12:1
SDR Mx Cam,cam from a canadian compagny
HD Spring
HD Rockers
Porting (middle and top end)
Maybe HD Head stud?!?!?
SDR CDI + 1000rpm

What do you think the best thing I can do?
What the best?? 426 or 440
Does a 426 or a 440 12:1 need a HD connecting rod? HD head stud?
How much HP does I will have with this setup?? near 40hp?!?

Here in quebec,this is hard to find 2R or Cr250 engine.I can maybe have one for 1500$CAN that is around $1300US.

What I can do :confused:

[dirtbikerider5]

I would just put the 440 kit in it. I have a 416 in mine and it is quick. With the 440 you need to put a new sleve in it and I have also read that there may be heating problems with the 426 if you do not put a new sleve in it.

[Wheelie]

Stroke it.:macho

My 440 stroker w/the stock carb and stock headpipe pulls away from my buddies 05 450 w/full exhaust, air filter and opened up air box lid.

[jsmith2232]

I went with the 416, it's alot quicker than it was, still has room on the sleeve to go to 426 if i ever want to and runs cooler and didn't need any HD camchains, headstuds and such. I am very happy with the build in my sig. I ran 60 or so runs on the dragstrip last weekend at silver and never got touched by another 400 and kept up with alot of 450's. That's a hell of a good feeling.:devil:

[quadracer3]

416 is the way to go,and get the fly wheel lightned.it will rev lots bette.r

[400exrules]

how high compression can you go witha 416 and still keep the stock studs and rod?

[jsmith2232]

I think i've heard of upto 13.5:1 but i'd stick to 11.1: or less so you can run pump 93octane.