noob need some basics

If I were you I would use the 68 440 if I could, as it will have a forged crank and the 72 will most likely have a cast crank. If I were you I would also set up a game plan as to what you want this car to be. Is it going to be a street/strip car, tubbed or mini-tubbed, just a motor transplant? A good vision of your car as you'd like it to be will set this in motion quicker. A couple items that you will need to buy are an 8 3/4 rear end, larger torsion bars, Schumacher engine mounts to fit your set-up, and a complete rebuild of the front and rear suspension systems. You are adding a lot of weight and torque and these areas need to be completely tight to handle this upgrade. I have never done this swap and there are some people here who have and who can fill in the details, but make sure that your underpinnings are up to task.

A couple years ago I bought a 71 Dart from "Lyle", a nice old gentleman. He and his brother had a 1977 440 motor built at Muscle Motors stuffed into this poor little old 6 cylinder Dart. No upgrades to the suspension at all, still had the small front drum brakes, the 7 1/4" rear, the 6 cylinder torsion bars, everything. The motor dynoed out at 450+ HP!!! I asked Lyle if he had ever driven it and he told me his brother had driven it about 500 feet, but couldn't keep the tire from spinning and put it in the ditch. I bought the whole car for $2500.00 and the motor is now in my friends race car. Although the job was not done exactly right, he did have A body fenderwell headers, homemade motor mounts on the 6 cylinder K frame, and there were no clearance issues. Unbelievably, he still had the 19" radiator in it!!! Trans crossmember was stock and it was shifted by the stock column shift. Trans was a big block 727. Anyway, hope this helps and good luck with your project, Geof