If you want to win, paint it red (or some other wild color), make sure it has spoilers, put a big stereo system in it, make sure it is dressed in SS and/or Z/28 clothes, and put the biggest motor you can find in it. That's it. Really quite simple.
No one wants to see a correct 1st gen camaro. Sorry. ("No one" = judges & majority of fan base). Bring your car so that the 2% of the public that recognizes it for what it is. Make some visual aids -- for instance, what a cowl body tag is and why that's important. Why the SS-327 across the aisle is an abomination. Etc. Then, leave before the awards are handed out, 'cause you aint gettin' one.
Here's the order of preference:
1) Rodded out, tubbed, and chopped. Camaro body with less than 1% original parts. Most combos impossible. No effort to restore anything (e.g., leather front seats, 20" aluminum wheels). Basically the Foose approach to car building.
2) Sort of the poor-man's version of #1. Less flashy upgrades, but probably still features some sort of modern interior -- instrument panels, seats from 1980+ car, etc. Probably tubbed to fit very wide tires and might be on slicks. Probably a 454 or 502 motor with lots of chrome detailing. Paint is red or some wild scheme. May have remnants of Camaros -- Z/28 stripes or SS nose stripe. Some sort of cowl hood, of course.
3) "Clone." Note that this is in quotes. To be a real clone, the car had to exist -- the thing sitting in front of you must represent something that at one time existed. In fact, most "clones" are not, in fact, clones of anything. If anything, these are concept cars or idealisms of what the creator wished had existed in 1967-9. So, we're talking about some random motor again -- 383 is a popular choice. Probably dressed up and maybe with multiple carbs. Paint is probably a normal color (primaries), but not representative anything factory. Interior is probably half-and-half. Maybe some factory seats with an Autometer gauge panel, for example. It's hodgepodge -- some stuff from deluxe interior + some stuff from standard interior + some stuff totally custom. Wheels and tires could be anything from 14" ralley to 22" aluminum, but won't be representative of factory. The best you can hope for is "period correct" with the ralley or maybe some Cragars.
4) Clone. This is pretty close to accurate. Nice cars. People who took a 6 and built it into a SS-396 with the right accompanyments. These cars are cool because, even when being true to what was available at the time, you can build a monster. 1967 SS-396 convertible, deluxe interior, disc brakes + 15" rally wheels, RS package, deluxe exterior, deluxe seatbelts, etc.
5) Original. With few exceptions, the original just isn't as nice as the "original on steroids." No tri-power carbs. No shiny Edelbrock components. No paint jobs that pop. Impressive cars, for sure, but not the car you'll remember later that evening when you're having dinner ... or when filling out a judging card.
Now (1) is usually a work of art. I don't like those styles of cars, but I can at least appreciate the art that went into building it. The cars in the (2) category are iffy for me. I don't like strip cars and these usually just look like wanna-be type cars. Usually it's just a huge blown motor + fancy paint. However, I'm definitely in the minority, because lots and lots of people prefer this look.
(3) is the real abomination. It violates every standard of decency because of the presentation. At least categories (1) and (2) are honest about what they are: some modern supercar built on the 1st gen platform. But this one is the one that makes us all want to scream. These are much cheaper to build, especially for the backyard mechanic who's good at building motors or painting autos. However, this makes the cars more "accessable." Few of us can drop $100K or more into a supercamaro or blown street racer. However, many (read: judges) can more easily see a base car with a crate motor, fresh paint, some interior upgrades, and "correct" stylings such as the z/28 badges on the 1967 car.
There will always be a bunch of (3) at the show and in varying levels of execution. Outside of the masterpieces, these are the ones taking home the awards. Count on it.
(2)s can also be annoying. The same way that pretty models get to stay fit because instead of going to work every day, they spend 4 hours in the gym working out. They get to be more beautiful than the rest because they don't follow the same rules. And, hey, don't like your nose? Then get some surgery and make it prettier. Don't like your headlights? Then, get some auto-surgery and become an RS. Still, at least these people are following the basic laws.
That leaves (1). This is the only category that has limited potential. Doesn't matter how good you're car would look with a candy-apple red paint job, once you cross that line, you've vaulted into category (3). Unless you have some freak of a car (COPO, Yenko, RS/SS 396 convert, etc.), you're car is just going to pale in comparison to any number of like cars from the above categories.