What's the proper way to bolt in the coupler at the splined end? The one I just purchased has a set screw with lock nut on one side and a bolt with 1/2 threads and a smooth section and on other end which need to go through the steering shaft with a roll pin?

I've seen a video where it says dimple the set screw into the shaft but I don't want to mess up the splines on the steering box.

Does the set screw end up on the void on the steering box input shaft?

Spline has a set screw and the roll pin goes through the shaft.

How far into the coupling does the steering shaft go ? Thanks Gary

You need to drill the column shaft. Did you buy this used or something? They come with pretty good instructions. Maybe there is a copy of them at their website.

The steering box should have a cut out area in the middle of the spline where the bolt would slide through. The bolt holds the joint from sliding off when tightened down. Set screw? never seen one on the same end . The roll pin as you say goes through the other end . If you have a hollow steering shaft the shaft should have a plug welded into the end, then drilled and pinned. A thin hollow steering shaft will cause the pin to shear leaving you with no steering. Double d joints have set screws, Is this what you have?

This is a new unused coupler in a sealed plastic bag. Reading the directions makes no reference to the strange looking bolt with nut that is threaded about half way.
This bolt is supposed to go through the coupler into the splines and it would gall the splines once penetrated through the other end.
I get the part about drilling through the shaft but doing anything to the spline area is confusing.

I think the set screw goes to the flat spot on the splines,,,,,,,I think

There is no flat spot on my splines. Set screw will go right into the splines and theres another long bolt that will hit the splines and go through the other side with a nut.

I have a flaming river colume in my 67 A body. They are a GM colume with Gm wiring. They told me simple plug and play. They lied. Had to cut my original colume plug and hard wire. Their diagram did not match what i had. No real help when i called.

On my 63 I went from power to manual steering. So all I had to do was add in this adapter to take up the room that the larger P/S box used. Its nice when thats all I am doing. Good luck with yours. Ron

I have a Flaming river coupler. The splined side that goes to the steering box has one set screw that is tightened were the roll pin used to go. So you are not tightening the set screw down on any splines.