350 header on a FC 250

Does the '23 350 header fit the 250? That big section is further forward on a 350 than a 250 right? If anything I think the 250 needs help down low.

I noticed some of the pro XC2 racers at the GNCC on '23 KTM 250s were using the longer 350F header (FMF).  I asked a couple of the team mechanics/tech guys and they told me it added more usable low/mid range power and some of the guys preferred the longer 350F one and some liked the shorter 250F one better.  It also looked like maybe the diameter was slightly larger on the 350F one.  I asked the FMF guy about it and he told me the opposite - longer is for top end power.  I'm not sure what to believe.

As far as I know, longer or smaller diameter will create more torque/low end power due to the scavenging effect (think of siphoning water through a hose) helps pull more air through the cylinder.

And a shorter or large diameter will help with top end, think you have such high rpm’s and so much air moving, a small exhaust will start to restrict. where with the short pipe you just need to get that air out and out of the way as fast as possible