I started on my Borgeson PS swap. It is a smidge out of line left and right which is noted possible in the directions. I called Borgeson and they said it happens but not often. A thin washer under the bottom bolt straightens it up. I am concerned a bit about how low the column will be in the car. I was hoping someone else who has done the swap can comment or post a picture of their column along with column length. I used the Borgeson splined bushing with a piece of 3/4" all thread and a piece of 2" conduit to get an idea on where this is all going to end up. I even cut out a 14" wooden steering wheel but I don't have a picture of that. In the picture below my home made setup is sagging a bit so when it is straight in regards to the steering box it looks like a 2 1/2" drop mount should work.
I had to open up the holes, use washers and heat and hammer down the top of the frame rail in order to get my shaft centered in the dash opening where it belonged. Unfortunately I don't have any pics at this time as I am in Florida and my car is back in Maine.
Just looked it up, 1" 48 spline x 3/4" 30 spline. You may want to check with them or Summit. They may have what you need.
I have the instructions somewhere. The column does have to be shortened at least on mine. Sort of labor intensive from the looks of it.
In the process of doing it on my 58. I took the front clip off. Wouldn't attempt it otherwise. But I'm no longer a youg'n.
I'd need help too, have to round up a few people or take it to a shop that fixes old cars that I know.
The box is definitely longer but I am planning on switching to a tilt column and smaller steering wheel. There is currently too much belly interference in that area..
Flaming River makes one and it's only $95.... It's definitely an odd duck but that is what the box is. Here is what it came with but I'm not sure I like how low the column is when it is straight off the box. http://www.borgeson.com/xcart/product.php?productid=1002
Did you use the factory column then? The factory steering shaft is 3/4" tubing and you weld that fitting on the bottom. All the aftermarket columns I looked at were 1" DD or splined shafts but not 13/16 36 spline.
https://www.summitracing.com/parts/brg-990040 The outer column is from a 65 Falcon. I may have to cut some. Don't know yet.