Exhaust headers - all the same?

[TallPaul]

My 2001 VTEC spec 1 cb400 has it's original downpipes and silencer and under the bike they're starting to blow, gonna be on the lookout for a stainless system to replace the (mild steel?) original pipes.

Question is, are the header pipes the same for all models of cb400? I'm guessing the later FI versions will have holes for a lambada probe but what about earlier non-vtec bikes?

[Mansie]

I would expect the headers to have the have roughly similar dimensions on all CB400 Superfours, but I am not sure whether the exhaust systems for NC31 (SF), NC39 (SF V-TEC) or NC42 (SF V-TEC REVO) are all interchangeable. On yahoo auctions they are listed with pictures but hard to tell the difference.

I looked on ebay and all I saw was old tat. What I would do is have someone make some stainless custom headers and collection box and then slip on a muffler of your choice.