I did a conversion on a buddies 55 and we used the astro van box and it works AWESOME. We ordered a high steer kit and just replaced one of the weld in bungs with a standard one and used a rod end.
If you are going to use the ford box, you can findF a tapered drill bit and drill it yourself.
If you didn't sink to much $$$ in the box it is definately worth looking for a ASTRO box.
Just my 2 cents
