How long is 55-59 steering column

[Fults1971]

Ive got a 56' steering column, but looking at may a universal column shift. I looked at the ididit columns, but they don't state the length of the column. I think I found a universal that would fit, but it considerably cheaper. I think ive read a few things about the length, but everything ive read says 30 inches. but my factory shaft is considerably longer. so im not sure how to measure the column; from spline to spline?