A couple of other suggestions, especially if it's a 2-door.
As said above, weld it right, and it should stay good. Brace as needed, and weld the trailing edge of the hinge, which comes from the factory with a very large gap. When I did it, I added a piece of steel rod to fill the gap, and welded over it. If you take the time to place the hinge right, the door will line up nicely with little work.
But the 2-door has other problems owing to the heavy door. First, make sure that the check mechanism is intact, and that where it mounts to the door is not bulging out or cracked. They made the check too long for the door, and when it flexes or fails, the hinges hit their own built-in stop. Hitting the hinge stop is what makes it flex outward and tear apart.
If you weld, one option is to take the existing check out, weld the hole in the end shut, and drill another about 1/8 inch further in. Grind the end off, and you now have a "special 2-door model" check, which will resist further tearing out. This works well as long as the door itself doesn't bulge or crack and the check itself doesn't fail.
You can also grind the stops on the hinges out a little, so that the door is able to open further and allow the check to work before it hits the stops.
Unfortunately, if you have someone who tends to fling doors open, even these fixes may not work 100%. My stepson's driver's door, unable to tear its hinges out any more owing to the remedies, has decided to tear itself apart instead: the frame of the door itself is flexing and the skin is coming loose, so now the whole door sags even when the hinges are perfectly aligned!
And finally, after you weld, remember to lube the hinge very generously. The hinges aren't easy to get lube into, but welding will cook out whatever is there, and it will wear fast if you don't get fresh lube in there.
