The major difference between 1/2 and 3/4 tons would be the springs. The AD trucks front end seem to be identical; I'm not sure if the 58 is the same. You say you're going to update the suspension so that shouldn't matter. After updating front and rear you've pretty well made it a 1/2 ton. Now you will need to decide if you want to cut the frame down to short bed.
Have fun and welcome to the bolt.
That's what it's all about anyway.
