would any of you guys be able to tell me if there is a big bore kit that i can put on my, 06 400 ac.4x4 auto? which my understanding is an eiger. thanks for any help in this matter

 

while I'm an advocate of mods for getting more out of your engine, I'd have deep misgivings about changing the stock displacement. In my opinion, that's the very best way to destroy your reliability. Once you start boring, you start breaking.

You should have bought a KQ or BF.

 

You'd probley be better off selling it. If you really want to try it, I'd go for a bigger carb (vinson) and port job. Other then that it'll be the 400 that could.