After Header install ?'s

[csdineley]

Hello

Well I finally got some headers after putting up with my cracked and leaking manifolds for awhile now. And today I got to test fit them before the snow started coming down. They're the cheap ebay stainless 3/4 chevelle headers. They fit well and look great. But I thought up some new questions.

1.) I need to have an O2 bung installed. Should I get it on the header collector or the reducer/ Y-pipe? Either way heated O2 or just a normal one?

2.) Collectors are 3" and came with reducers to 2.5". My stock exhaust is a 3" single stainless setup up from the cat all the way back. But the y-pipe is 2.5" so the question is should I have a 3" y-pipe made up or is there a befit of reducing it to 2.5" through the y-pipe?

3.) Once installed I need to find a way to get it up to the shop to have them weld up the bung and y-pipe. Any thoughts?

Thanks