I know I'm a bit late to this topic but let me say this, I had a similar situation when removing the stock exhaust manifold, also on my '97 SE-R to install a cheap eBay header.
We used PB plaster
We used vice grips (many different sizes)
We used a torch
We even had my one neighbor, a guy so big and strong, who can probably lift an entire car and could crush my skull with one hand, try to remove it.
It was all a no go.
So in the end, I used vice grips and ripped it apart slowly by turning the metal and cutting into it. Got the stock primary manifold off, got a cheap $8 plug taper from Nissan to go in the empty EGR hole for the new header, and ordered a new EGR pipe. Got it from Nissan a week later for like $40. Kind of sad that it cost $40 for the new EGR tube when the header itself was only like $140.
I'm sure 10 years ago, it would have been much easier, but rust fucking SUCKS
Last edited by Storm88000
on 2013-03-21
at 04-33-35.