Choosing The Right Machine
Before we go any further lets talk about which Ducati you should buy, and those models best suited for the sport of historic racing.  Maybe you already own a Duc single, something to think about here is; will it suit your purpose, and will is be competitive within the class? Ducati has built several models of varied displacement of their ohc single cylinder machines over the years, as well as a number of very sought after GP racers, which includes machines such a the 100 Gran Sport from 1955, the dohc 125 Grand Prix of ‘58, the 175 Formula III (that cost more than a Manx in 1959!), or the 250 Formula III. Over the years Ducati has produced some wonderful racers, and they earned their place in road racing history. 
Lets focus on the standard machines of the day, those “mass produced” if you will.  Lets also take into consideration that most sanctioning bodies only cater to particular displacement classes, in most cases these being: 200cc, 250cc, 350cc and 500cc in Grand Prix racing, and usually 350cc and 500cc in Production competition. With that said, why search out a road going 125cc machine or even a 160? Don’t get me wrong, as both the 125 and the 160 are fun little machines, though neither is competitive in road racing at this point in time. It should also be said that WCBR has successfully used a 160 in Premier-Lightweight Trials competition over the years. As far as road racing goes though... forget it, you’ll get your doors blown off. Ah, I know, you can pump it up... yada, yada, yada.  No you can’t! Sure, you may get it to 175cc, but that’s it, no more, and it still slow, so bury the idea.
The first question many ask is, what is the difference between a “Narrowcase” and a “Widecase”? In plain easy terms: A “narrowcase” Ducati is easy to identify, as its engine mounting lugs on the cases are the same width front and rear, whereas a “widecase” has a full-width rear mount.  There are other differences as well, but a number are of the unseen type.   Since the engine mounts on the case are different you’d have to assume the frames were different as well. If you’ve assumed such, you’d be correct. There seems to be a difference of opinion when it comes down to which is better, the “narrowcase” or the “widecase”.

I’ve heard all the arguments, and I still say the “narrowcase” is the bike to have, and here’s why...
1) Age. I always prefer the older machine when competing in historic events. Why race a late model bike?
2) Weight. Whether its motocross or road racing, weight is a very important factor, thus the “narrowcase” wins.
3) Parts availability. Since more “narrowcase s” was imported, you’d think parts were more common, right?
4) Performance. Since the early 250s far out performed the later 250WC or the 350s, it’s obvious.

You’ll no doubt hear the other side of the argument from one of your buddies or that guy on the phone trying to sell you something, thus we’ll go straight to the pros of a “widecase”, and it goes something like this... 
A) The engine cases are stronger.
B) The frames are stronger, they don’t break the engine mounts, and don’t flex.
C) The gearbox is stronger... yada, yada, yada.
Of course we have the cons, some of which we’ve already touched on when discussing the pros’ of the “narrowcase”, so we’ll go into a bit more detail here.
D) The cases may be stronger due to the additional webbing across the back, but we have never found this to be a weak spot in the “narrowcase” engine.
E) Sure the frame is stronger; it’s wider and heavier too.  The “narrowcase” will break its rear engine mounts sometime during its racing career and this must be dealt with accordingly, which we’ll get into later.
F) Gearbox being stronger? I have no idea where this claim came from, as the “NC” & “WC” 5-speed box shares more than a fair amount of parts, thus its really an incorrect statement.
As far as cons? I’ll list them here...
G) They’re heavy.
H) They’re heavy.
I) They’re heavy!
J) The 350WC crank is unlike that of the “NC”, it weights more for starters (2-lbs), and even looks a bit odd.
K) The 250WC crank has a longer rod fitted than a “NC”, thus performance suffers.
L) The 450, all of which are “WC” models, come in two frame types, and just suck! More later on the 450.

Have you gotten the impression that I’m not too keen on the “widecase”? Da! Its not that I dislike the machine, we raced a 350WC, but if your looking for a single and want to go fast, buy a “narrowcase”, simple as that... they’re lighter, they’re available, and they’re cheap. Easy choice, isn’t it?
Late 1983... Mike Green's first Ducati, a 250,  nearing completition at WCBR shop in Dublin. It's first outing would be Las Vegas vintage race in November '83 where it finished 4th in the 250/350 race.