I'm looking for some feed back from 400ex owners who have installed the fmf powerbomb header. How does it feel power wise etc? Thanks.

 

I would not go with a aftermarket header, You have no engine work and the stock headers work better than the aftermarkets. I have heard if u shave the welds inside your stock header it helps improve flow.

01 Raptor--Big Gun Pipe, Prm Skids
00 Warrior--Blackwater tires, hitch,sproket, nerfs
00 Wolverine--SuperTrapp pipe, Uni Filter

 

I plan to go to a 416 or 426 with all other usual mods, cam , piston etc.

 

I plan to go to a 416 or 426 with all other usual mods, cam , piston etc.

 

I put a Powerbomb and Power Core IV-2 on my 400EX. I put them on at the same time, so I can't say what either one alone would do, but I can say I gained a fair amount of top end. However, I don't think I gained much bottom end if any. The engine now has a slight "bog" at low RPM in second gear. I've heard it said to stick with the stock header if you've got a stock engine. I see a 440 somewhere in the future, so I can live with it for now.