First, decide what you want as the end result and then find a C3 that will suit your needs.
Ask yourself, do I want a car I can purchase and cruise in, do I want a racer, or do I want a show car, all original or custom.
My needs were, it had to be a big block car, it had to have ac for my wife and it had to be as close to original as possible.
In the past, I have purchased a couple of projects started by someone else and they turned out to be nightmares.
Never again!
I purchased my 73 big block 7 years ago.
I found it for sale at a car show and it was in beautiful condition, mostly original, with minimal to no rust.
My plan was to do a complete body off restomod and build a hi performance sports car that looked mostly original on the outside but was a monster underneath.
Be mind full that the drivetrain on these cars was not designed for hi performance and anything over 450 hp will require you to upgrade everything and it is extremely expensive to do so.
Some people do a little at a time as they enjoy driving their cars, others, like me do it all at once.
Good paint and body work has become very expensive.
You’ll see threads where people have spent $15k to $20k for a good paint job, but if you want it perfect expect to pay $25k to $30k.
Good luck and keep us posted!

 

You need to ask yourself some very pointed questions:
1. Are you certain about a "restoration"....like factory original 'all original to the nut/bolt level' restoration or just a refresh of whatever works better kind? There is a major difference between them. Original good condition used parts in some cases are very expensive.
2. Have you driven an older Corvette and are okay with the fit/finish and experience that comes with that era of vehicle. They do not drive like a modern car without a lot of modifications and money/time.
3. Buy the year that appeals to you from the get go. If you really like the early C3's then get one of those off the bat. Don't buy the middle years or later years if you are dead set on the early years... and vice versa. Nothing kills a long project more than when the newness factor wears off.
4. And as advised already... lots of pictures and notes to go with them... looking at some pictures doesn't always explain the entire process. The notes should dictate order of removal for complicated processes. Tag it and bag it. This will also consume more room than you realize.

DON"T BUY A BASKET CASE.. even a free car can become too expensive to justify the resources.

Best of luck on the search.