This is a bit subjective - if using a wide space freewheel, a wide old chain such as a Regina Oro gives a very authoritative bite that some people like . A stiff chain such as the Oro gives a unique feel.
But - now everyone will jump on me, if using a narrow freewheel especially, a modern 9speed chain will do wonderful things too. It is so flexible that it is quiet (won't hit the front deraillieur so easily) and their profiles seem to enable them to shift very well. I use 9speed chains quite a bit on any narrow freewheel and I really like the performance. Much better than an 8speed chain on an 8sp!
Now, modern chains wear out really really fast, so that's another factor.
The sedisport chains Greg reccomends are also a great option.
And of course, the best steel freewheel is the Shimano DuraAce -
Mike "running for cover" Kone in Boulder CO
> Date: Fri, 10 Dec 2004 18:26:12 +0000
\r?\n> From: rodk3d@comcast.net
\r?\n> To: classicrendezvous@bikelist.org
\r?\n> Cc: internet-bob@bikelist.org
\r?\n> Subject: [CR]best chain/f'wheel on Super Record drivetrain ???
\r?\n>
\r?\n> Hello,
\r?\n> I'm about to set up a Super Record drivetrain on a bike with a 126 rear end and
\r?\n> will be using Suntour (friction) bar-cons.
\r?\n>
\r?\n> I'd love to hear some opinions on which freewheel and chain will give me the
\r?\n> best possible shifting combination. I'm open to vintage and new, whatever works
\r?\n> best.
\r?\n>
\r?\n> thanks!
\r?\n> Rod Kronenberg
\r?\n> Fort Collins, CO
\r?\n> Rod:
\r?\n> I think that is a wide-open question as you've framed it thus far, and would be
\r?\n> virtually impossible to answer with any authority, other than to state personal
\r?\n> preferences. Frank Berto spent years studying this very subject.... You may want
\r?\n> to get much more specific - best under what circumstances? With what gearing? On
\r?\n> what kind of frame geometry? What is best / important to you? If absolutely any
\r?\n> components are acceptable, then go for some twist-tooth super-duper-shifting
\r?\n> cogs and a modern chain of your choice.
\r?\n> If you are thinking of a "period-correct" racing crossover setup with
\r?\n> closely-spaced freewheel cogs and a double crank with no more than an 11-tooth
\r?\n> difference, that's much easier to discuss, but still a pretty broad subject.
\r?\n> All of that said, my general favorites on my 126mm-rear-spaced bikes with no
\r?\n> more than a 24-tooth max. freewheel cog (it's flat here in the my area) are the
\r?\n> later six-speed Winner freewheels and Sedisport chains. The narrow Sedisport
\r?\n> works well with the vintage narrow-caged Campy (and other) front ders., and
\r?\n> shifts well due to its "bulged-link" design. A bonus is that neither of these
\r?\n> components is particularly expensive. The chains (at least modern descendants)
\r?\n> are still made, and the Winners are reasonably frequently still available NOS.
\r?\n> Another nice option IMO is Regina CX with a CX chain, particularly if you want
\r?\n> to stay "tutto Italiano," but these are very difficult to find NOS now....
\r?\n> Greg "unchained melody" Parker
\r?\n> Dexter, Michigan