Manual vs Pwr box input shaft

[bbscamp]

I'm going to install a manual box (small sector) onto the 64 Valiant (power steering).  I'm happy about the Pitman arm just swapping over!  However, putting the 2 boxes side by side, I see that the input shaft on the manual box is smaller than the power one.  That means that the column shaft is now too short AND is has the wrong coupler.

does the firmfeel  adapter take into consideration the change in inputs shaft diameter?   are all manual smaller than power on the input side too?   what adapter can I use?

[Bill_Reilly]

https://www.reillymotorsports.com/store/product.php?productid=16141&cat=254&page=1

On a budget, someone also mentioned the stock coupler from a dodge van with manual steering will adapt you over....

Power boxes are all 5/8" X 36spline and manuals are all 3/4" X 36spline.