Well me and a buddy of mine are going to swap out the headers on my 2000 mustang (passenger side has small hare line cracks) and were going to use the 94 mustang headers and was wondering what all would need to be changed if any for the swap. And also are the 94 headers a good upgrade? They look like they flow better then the 2000 headers.
I was going to buy the Hedman headers off summit but heard that the 94-98 headers were about the same....

 

The 94-98 headers are a good upgrade to the stock/crappy 99-04 manifolds.

You will need to get the mid pipe (where it connects to the headers) opened up a 1/4" by an exhaust shop.

 

well we got the headers on.....changed the sparkplugs.


Found the driver side header back flange for the last cylnder was broken off...And like he said the flanges need to be changed on the mid pipe. But everything else dropped in fine didnt need to move to many things around.