Dear Car Talk,
I am restoring a 1962 Fiat 1200 Roadster and in addition to the rust being removed and new metal being fabricated, I would like to find suspension, brake, and engine replacement parts. In fact, I might need to replace the 1200 engine. Can you recommend sources for the replacement parts and might there be a newer engine that would fit in the Roadster allowing me to use the existing clutch, transmission, and rear end?
Doc’s Toys
You need to join classic Fiat forums, good chance of connecting with an old Fiat authority there.
Try Hemmings the classic car magazine/website, search the internet for Fiat forums, including ones in Italy. Use Google translate if you have to or learn some Italian. Finding parts for this 53 y/o car will be an immense challenge.
As far as a replacement engine, Miata. Small and more powerful that the engine you have. Use the Miata transmission as the Fiat trans will be a nightmare to adapt. Use the front part from the Miata driveshaft and weld it to the Fiat driveshaft. It is likely easier to remove the Miata fuel injection and install carbs. It is very specialized work to adapt a later engine to an older car.
It will be simpler to rebuild your Fiat engine than to swap in one from another car unless it has a big hole in the block or the crank is broken.
Your project is a labor of love bordering on masochism!
It will take all your patience and perseverance to complete it. As well as a great deal of money.
Some years ago a friend, who is a financial advisor, restored a '50s Triumph TR3, and spent $14,000 since the car was basically in good shape and did not need an engine rebuild or replacement.
Your transmission, clutch and differential would not stand up to a newer, more powerful engine. Besides, an engine change could hurt any collector value.
FIAT Stands for Fix it again Tony
Also you might want to edit your post and remove your email address, it is never a good idea to put it on an open web site.
Volvo’s right about the email address.
I admit, I’m jealous about the Fiat. I always had a weakness for the old ragtops sports cars. Having an uncommon one should add to the pleasure.
Here’s a Fiat forum, lots of links. http://www.fiatforum.com
You may not find lots of discussions on the 1200, it’s pretty rare, but folks there may have good ideas on where to look for more info.
You have a neat and rare little car there. What you need to decide as a first step is to separate the two stages of what it’s worth when done and what you spend redoing it. If you redo the car because you love it and plan on keeping it then it’s a go. If you start fretting money (within reason of course) that will cause a lot of angst during the process and it can start eating on you to the point where you start to question your own sanity. Been there… 
My suggestion would be to keep the original motor rather than adapting something else. Can’t say as I’ve ever been into one of these engines but it should be grade school simple.
Originality generally means more valuable although that factor (see above) can be omitted.
I’m a sucker for older 2 seater cars like this so there’s some inherent bias on my part.
Good luck. At least reproduction parts are available for MGs.
I have only seen a handful of Fiat 1200 roadsters and that was in the late 1960s thru late 1970s. I would also suggest getting advice from clubs and forums before spending time or money on a project that may be nearly impossible. They are really nice desireable cars. I’m not trying to be negative, just realistic.
This is a great looking car and I wish you the best of luck getting it restored. As others have already said this will be a hard and expensive task. I’m assumimg that you knew that already.
…a financial advisor, restored a '50s Triumph TR3, and spent $14,000 since the car…
So, @Docnick was the car worth the $14K he put into it plus the purchase price? I’d guess not. Hopefully he didn’t view it as a financial investment! These kinds of projects rarely are. They always seem to benefit the next guy more than the restorer.
Unless someone’s lucky enough to come across a high value classic, restorations almost always cost WAY more than the resulting sale price. Figure fifty cents on the dollar, I hear. So it’d better be a ‘labor of love’.
If the OP is looking for a more easily doable Fiat, how about the 124 Spider? Lots made, lots of parts available, just as much fun to drive (if not more so, with the bigger engine).
@mustangman The “he” was a “she” and she had another car as well. She’s a stunning blonde who loves convertibles (roadsters) with classic flowing lines.
Economics did not enter her picture, but I mentioned this example because this car did not need a lot of work and we live in a dry area with 1/16th the rust factor as around the Great lakes. It was a cheap restoration.
Jay Leno would be the first to tell you that classic cars are a lousy investment.
I used to own one of those, 1961 Fiat Cabriolet. The body continued until the 124 Spyder came out, but in 63, they used a 1500cc version of the engine that went into the Spyder. The handling was not as good with the later engines though.
I owned mine in 69-70 and I often said that if you wanted to learn car repair, get one of these. I only put about 7k on it during that time, but I replaced the head gasket over a dozen times. The aluminum head was not made from the same alloy that is almost universal today, it was a softer aluminum.
Your engine is a 103G model. This is essentially the same as the 103D, 1100 cc engine that Fiat used in their standard sedans of that period. You can use a 103D head on this engine but the ports are smaller.
The bad thing about this engine was the bolts used to hold it together, they were bad about breaking. I had to do 4 major overhauls in that 7k as well due to broken bolts. They are high grade metric bolts, but bake in 69, metric bolts were hard to come by, especially in the grades needed for this engine.
I had a lot of trouble keeping the flywheel on too. It did not fly off, but occasionally a bolt would break and the head would get stuck between the flywheel and the clutch plate. Those bolts were not easy to find back then. If you rebuild this engine, make friends with your Fastenal dealer, wish they had one back then.
I think, memory is fuzzy here, that the washers used on the head bolts were cone shaped. I had never seen this before but now I know that that is a belville washer and they are not reusable, which would explain all the head gaskets.
The car was a kick in the butt to drive, when it was drivable and you will learn more about cars fixing this one than you could get out of a book. Even back in 69, parts were not available, even through the Fiat dealer, so I not only learned how to replace parts, I learned how to repair, manufacture or rebuild all the needed parts.
All I can say is good luck, you are in for an experience and an education.
Edit: If you can find a shoe repair shop or a cobbler, it will be helpful. I had a cobbler restitch all the seams in the leather seats. I got a clear 8 mil vinyl from Sears and he made me a new back window as well as stiched the rest of the rag top back together.
Seems like the OP should carefully read @keith 's first-hand account of the effort to own this car when it was only 8 years old, let alone at 53, at least TWICE. At that point the OP should re-evaluate their finances and desire to restore this car. Even with a perfect restoration, this thing will be a money pit.
I hereby change my earlier post, forget the engine rebuild and find a modern, reliable engine and transmission and rear-axle to swap into this car. You should re-wire the entire car and upgrade ALL instruments to modern versions, front suspension included. Heck, its probably simpler to buy a Miata and cut the floorplan, remove the body and drop the Fiat over it. Weld it back together and now you have a Fiata that will be reliable. Even as a fab-job, it will still probably be more structurally sound that the original Fiat.
Or save a WHOLE bunch of money and buy a new Miata (the 2016 version).
Right now those cars are for sale in Europe for up to 28k usd, left hand drive. IF it is standard.
Keep it as from the factory, have a lot of fun with it and enjoy life.
Best regards
Klaus
Edit:
OOps, that was a loong link for pics. Sorry.