Charlie -
The 41-46 box is a direct bolt in - no alterations, no cutting - it just bolts in and it is a circulating ball steering box - arguably the best type of steering box made. They were used on the early Chevy cars, the early Mustangs and others. That's what you need to give you the best steering box for your truck, unless you are going to a clip front end or go to a custom made street rod front end.
Joe
