Actually the 57-59 column is 4" shorter than the 55-56. I used a 57 column on my 56 when I converted to PS. I also used a wheel from another GM vehicle that is smaller and works quite well. Yes the stock 55-56 wheel will be much closer to the dash and may cause some issues. To the best of my knowledge, GM used the same size splined shaft from the 30's through the 90's.
Fred

1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine