There are lots of things to consider before doing a major project like this!
First of all, if you do it to save money, you are fooling yourself. In the end, you are money ahead buying a complete or partially complete running car. If you have never done this type of thing before, you really can't imagine how much all of those small (and not so small) parts cost! It is definitely a domino effect........you can't put those old bolts in your nicely painted manifold, on your nicely painted engine, on your nicely painted chassis, etc......You get the picture......Figure what you think it will cost to make the car perfect.........then double it and add a few more % points and you will be close! The closer to perfect you want it, the more expensive it gets. You will save money on any labor that you can do yourself, and you can even save money on labor that you don't do by disassembling and cleaning stuff before dropping them off to whoever does the work....
Whether your doing a restoration, or restification, research is crucial. The first thing to do is decide what you want the car for........Is this going to be a 100 pt show car or just a nice day driver or an 11 second drag car? I decided that I wanted a somewhat tricked out, fast, nice driver, rather than a show winner. Since I was planning from the start to modify it, I didn't go crazy trying to find a numbers matching, G.M. air in the tires, 2000 mile original that's been stored in a barn for the last 30 years. As described elsewhere, mine was definitely a basket case! But I sleep better at night knowing that I am not changing a '71 Judge convertible or the equivalent.
Secondly, time is a big consideration when doing a project such as this. If I had a nickel for every hour I've spent wire wheeling, degreasing, sand-blasting and painting minute/non descript parts, I'd be able to pay someone to do it!
Space is a definite priority for a project of this scale. I consider a 2 car garage an absolute minimum for a frame off, unless you store the part your not working on (body or frame) outside. I have a 3+ car garage, that is not big enough!!!! The most irritating thing about not having enough room is that in order to do any work on the body, I have to move a few bikes, garbage pails, toys, lawn mower, wheel barrow, hoses, boxes etc just to get to the car! It is a real pain.........
You also need storage for all those parts that are awaiting their turn to become new, as well as for the finished ones. For the small parts, I use heavy duty, zip lock freezer bags, marked with a sharpie pen as to where the contents originated (believe me, do not overlook this step!). I then either store the bags in well marked boxes if the part is not going to be used in the near future, or on pegboard hooks if they are. Even with all this organization, I still can't find some stuff (maybe it was the 2 moves I've made since starting this project?) Large items such as the hood, fenders and such are stored on a rack I made from a few 2X4's, hanging from the ceiling. This gets them out of the way, and helps prevent damaging the parts. For the heavier stuff, like cylinder heads and intakes, I made a set of shelves out of 2X4's and 1/2" plywood. It really helps if you have a large attic or basement (I have neither!) to store stuff. Take LOTS of pictures (I wish I had taken my advice earlier. At least now I have an intimate relationship with the factory parts books!) Try to get a car that is as "assembled" as possible. Mine came in a bunch of boxes, but at least the last owner bagged and tagged a large percentage of the small parts.
A good set of decent tools are also needed, but to go this far you need at least: a complete SAE socket set (including 1/4", 3/8" and 1/2" drive and assorted breaker bars, extensions etc.) a complete SAE open end wrench set, good screwdrivers in various sizes, a good 1/2" torque wrench, the biggest compressor you can afford, a 1/2" impact wrench, die grinder, da sander etc.
For small parts rust stripping and cleaning, a heavy bench grinder with a stainless wire wheel is hard to beat, but a bench top bead blaster is better! For the larger stuff, I use a 4.5" electric angle grinder with a knotted wire brush on it, and it works very well, but it's slow. A siphon or pressure type sand blaster works pretty well too, but it makes a HUGE mess (you will be picking sand out of every nook and cranny of your (and your car's) body for weeks!).
For degreasing, cast iron and steel, I use a 17 gallon galvanized tub with a mixture of Trisodium Phosphate (TSP) and water. Always use eye and hand protection in case some splashes! Mix it up nice and strong and let the cast iron and steel parts sit in it (my valve covers and oil pan sat for 4 days). Lye is even stronger, but a lot more caustic. When you are done, make sure you CAREFULLY transfer the used stuff to a sealed container, and bring it to wherever they recycle oil and stuff in your town. Tell them what it is, and they will dispose of it for you! I can't stress the importance of protecting your skin/eyes from this stuff..............the TSP is not too bad (It tingles if you get it on your skin! Ask me how I know!), but lye is truly evil stuff!
If you will be doing any major body panel replacement, a good wire feed or better a MIG welder is almost a necessity. Just watch the heat settings, especially on body sheet metal, as the heat from a continuous weld bead can (will) warp the metal. Small "stitch" welds working around the edge of the panel and cooling them with a wet rag works great!
There are times when you will get a bit discouraged, and feel like going down to the Pontiac dealer and buying a brand new WS-6 Firebird or Grand Prix GTP and selling your project for pennies on the dollar! When this happens, it's time to close the tool box, and do something else for a while. I always find that surfing the Classical Pontiac Q&A section usually gets my interest back! If you reach a snag on one part of your project, make it a point to do SOMETHING on your car once a week or so. I always find that degreasing/ wire wheeling/painting parts and subassemblies is a good, low stress way to make some visible progress. Also, don't let the non believers get to you. I have a friend who claims to be a car guy, who can't see the whole as the sum of it's parts. He is very negative whenever the subject of my car comes up. I guess he has no idea of how long it takes to do this type of work alone. Most people who look in my garage see a multi colored P.O.S. body shell, that will never run again, instead of looking at all of the progress I've made on the chassis, engine etc. At least my wife is very supportive of the project, which really helps a lot!
Making a rusty, crusty, nasty greasy part look like the day it came from the factory is the reward for all of the effort! I view this type of work not as a means to an end, but as an end itself. My car was a basket case when I bought it 3 1/2 years ago, and it is still in the basket! Just remember that a car is made up of about a million little parts. I still have a long way to go, but at least some of the parts are a bit shinier though!