Kicking around the idea of building a square tube chassis on a wrecked Dart sport I have laying around that I used for parts. What wall tubing should I be looking at? I'm not real worried about it being certified when I'm done...it will be mainly street driven

I would go at least the smallest legal, for possible resale value, As well as being able to upgrade to 8.50 if you ever decide. 2x3 around .100 is often used, mine is .125. Roll bar, 1 5/8 min with what ever is gauranteed to pass
nhra tech.

downside weight ,upside easy to make it straight

How many attaching points to the body are the norm? I know the rear obviously has to be attached at the bumper area.

you could have bought Jimmy's old chassis for a fraction of what it will cost you to fab a new one. it may still be available

What was he asking?

I made a 2x3 tube chassis from front to back, did not cost that much. I used .120 wall thickness, ladder bar rear suspension.

That setup looks great I'm planning on retaining the stock front suspension and frame rails so I won't have much tube to buy. The factory rail measures 2x3 inside so I can slide my tubing right in and weld it all up. Plus it will help me start off square with the car. The more I think about it I might end up just using the 68 valiant I bought for parts a couple months ago, it's got better sheet metal

Nothing wrong with square tubing. But, they offer it in .083" which covers NHRA requirements. 2X3 .083" is right at twice the weight of 1 5/8 round chrome moly tubing. So it is important to try and get the thin stuff.

The frame needs to be supported to the body at the front of the rocker panel. Rear of the rocker panel and at the rear of the car(Bumper as you said). Supports can be made with 2X2. For the ones rear of rocker panel where the main hoop sits I would go 2X3.

The downside to square tube is no matter what you spend as far a cage and chassis parts you still have a square tube mild steel car. The value will be less as many who have these for sale find out they can't get the tube chassis prices. I have seen some real nice cars for sale that I first ran to finding out they were square tube or round but mild steel cars. It's all in what you need or want.

Trying to sell square frame race cars seems to be a waste of effort. I have a '70 Duster with bushels of $$$ in it but it has that darn square tubing ..so it will set 'til it rots to the ground.

I don't plan on selling it anytime soon after I finish it so I'm not too concerned with that aspect. I've added up my cost on materials to get it to rolling chassis (some stuff I already have) and I'm just under $2200. Surely I could get that money back If I needed to