If I go with a new IM (Either Blox or SK2) will it still be compatible later when I want to go LSVTEC?

 

No, the bolt patterns are different.

 

Just have a custom job done on the stock manifold.

 

no... just wait for the new head (c1 or c5 im assuming) then get the manifold that will fit that

 

Would the same apply for a header?

 

Whoops, I guess I mis-read that. So yeah, what these guys said.

 

Not where it meets the head, but where it hooks up underneath some mods. will have to be made to make it fit right.

 

don't spend any money till you get the big stuff out of the way... the LS/V is a huge build... and with all respect it sounds like your not 100% positive what to do about it all... are you doing this job urself?

 

I would probably do most of it myself, I'm trying to do enough research ahead of time to see what will be compatible.

 

that's good... just make sure that you are confident in what your doing before you go about anything your not sure what to do... i would also suggest having someone around that knows it better than you.... just so that if things go wrong (and they will) you have another set of hands.... and some easy advice