[mickmate]

I believe you can build a square flat frame with basic tools. You can do a lot with some simple tools to stay square off corners and do a lot of diagonal checking while you're tacking together. Welding needs to be done systematically and balanced for shrinkage. Avoid the temptation to blast the whole chassis out in an afternoon, weld shrinkage is bad news on chassis'. When you're done with a chassis the suspension has so much adjustment it will always align. Cobra Restorers sells a copy (albeit incomplete) of most of the critical dimensions of an original chassis. Check out the scratch builders forum on here for some good reading on it.