Are all headers the same?
 

Does anyone know if the classic exhaust manifolds are the same as the new age ones?

am sure there diff mate iirc to be on the safe side ewait for someone else to secound this and to be extra safe wear a condom!! oj i would stick to buying a classic fitment one that way there will be no issues afterwards mate.

I'm no expert, but I'm sure headers are all the same fitment. Only difference may be in where the sensors go in about I think. So classic headers will bolt on a newage etc.

Someone else will explain in more detail hopefully.

All classic Imports 92-96 have a lambda boss in the O/S piece
97> The design of the runners on the N/S piece changed
2001> All cars (except TwinScroll) have a Lambda boss in the O/S piece

All UK Classics have Lambda boss in the downpipe.

Much as Fiestaboy says.
Headers 93>2005 are interchangeable. However there are three basic designs.
93>96 are bulbous and may flow slightly better. They have a lambda hole in the driver side collector.
97>00 are slimline but no Lambda sensor.
01>05 are exactly the same but with the Lambda sensor in the drivers side collector.
Do not mix bulbous with slimline.
06 onwards and the situation is a little unclear because we have come across cross pipes and collectors with slightly different dimensions which makes swapping these a bit of a nightmare.