Super55,
Grigg covered your question well if you still have more or wish to go this way you should take a look through my pictures as well. I used the same box as Grigg but kept the same axle. It's all explained in the truck build thread for my 56 I tried the 70's 2wd box rout first and found there is not enough room on the big bolts the tire hits the box in a right hand turn.
