Topic: is this possible? an exhaustive disagreement...

[73hutch]

the other day I put up a wanted ad on a local forum for a 77-78 cb750 exhaust. one person came through and I picked up the pipes today. when I got home I noticed the pipes were smaller than my other 750 pipes and the exact size of my 550 pipes. I notified the guy and he stands by his word that these came off of a 1978 cb750 supersport. I honestly don't see how that is even possible. they are clearly cb500/550 pipes. is there anyway possible he is telling the truth or knows what he's talking about? am I missing something? clearly you cant put those pipes on a 750 correct?
I've posted a photo, the pipe on the left is my cb750 the one on the right is the one he sold me

[chewbacca5000]

Do you have a 77-78K or F?  These exhaust need studs will not work with stock K spigots.  Need the F studs, hardware too.

[73hutch]

I have a K

[madmtnmotors]

The 77/78 K models mount the same as the 77/78 F models (i.e. studs with split collars). Neither the K nor F models used spigots after 1976.

[Stev-o]

Since the 550 pipes are smaller, it might be possible that they were on a 750?  But that does not make it right. 
Take em back.....

[754]

Look at the bends.550 is straight up 750 is slanted.. Even if they fit the head they cant fit the bike..
Look at the sideview.