What more can I say? They made less than fifty, and those weren’t supposed to be for release. I wasn’t devastated, not being a huge 'Vette fan, but my buddy is. He doesn’t know why either.
All I ever heard at the time were rumors, so I come to the Informed Few for an answer. So I can bring some peace to my friend’s tortured soul. 
Peace,
mangeorge
IIRC, Chevrolet was in the process of developing the C4 (what would become the '84 Vette) and did not want to spend the time (or money) to update the soon-to-be-defunct C3. The '83’s you see are actually left over '82’s.
What Mr. Blue Sky said, plus, IIRC the '84 was released in early '83 (March?), sort of like an '83 1/2.
I’m guessing the '84 might have originally been slated for release as an '83 model, but because it was such a radical departure, they ran late getting them into production.
They took that year to retool the Bowling Green plant for production of the C4. They produced 47 1983 models, but none of them were sold.
The Corvette museum has an 83 model. They have a very informative tour, also.
Didn’t it have something to do with a failed “crossfire” injection that caused…umm…mild explosions?
According to a quick Google search, the 83 Vette was actually the test of the design for the 1984 Vette. Somewhere between 44 and 47 were built, and the Museum holds the only surviving one, #23. These cars were the only Vettes with 1983 serial numbers, as factory problems pushed the cars back to the 1984 model year.
-brianjedi
There was supposed to be a '83 C4 Vette. However, the design was late and the process for building the car was significantly different compared to the C3 (68-82) model. This led to major quality control issues. The pre-production cars were not up to minimum quality standards. By the time the plant had solved the issues it was so late in the '83 production run that it was released as an early '84 instead.
The national corvette museum in Bowling Green, Kentucky indeed has one of the very few remaining '83s. I looked at it when I visited the museum and the fit and finish of the body panels is horrible. Gaps between doors and fenders, and doors and rocker panels, as well as the hood are all large and uneven. Panels are wavy, etc. It’s easy to see why it couldn’t be released in '83.
/Markus
Nope. The new 1984 model, which would normally be released in the fall of 1983, was release mid-1984…around March…and was often referred to as the 1984 1/2 Corvette.
Notable: GooodYear Gatorback tires made their street debut, the 'Vette handled above .9 g’s, it had an awful pogo stick-like shock setting, and digital dash.
And if you do happen to buy an '83 Corvette on the underground market, the Secret Service will confiscate it and throw you in jail because they were never officially released and are still considered the property of the United States Government.
:smack: No, sorry, I’m thinking of the '33 Saint Gaudens double eagle. Carry on.
Thanks to all. I’ll pass this on to Mike.
BTW; Corvettes always (pre '84, anyway) did have problems with fit and finish. Have they resolved that issue in the newer models?
Peace,
mangeorge
I recently sold my '95 vette, and while it was much tighter than the '77 my dad had when I was a kid, it was still a far cry from something like an Acura NSX. I can’t comment on the brand new ones.
I think Corvette lovers just accept that this is a big heavy American car without Japanese tolerances.
That’s because they are so much more fun to drive than the Japanese ones. 
Yes, I own one. A 1971 with a 454 and a 4-speed.
/Markus