modifying a 1.6l manifold
 

I was told I can take a 1.6l Manifold cut the end runners off and lenthen them is this correct for a 1.8L?

I'm assuming you're talking about an exhaust manifold. Why would you do that when you can sell the 1.6 mani and buy a 1.8 mani instead.

yeah just buy the manifold, it sounds like you'll pay more if you fabricate it, lol...