Stop in for a cup of coffee

Princess Valiant said
the floor shift 3 speed was available only after 70. 1970 was the first year for the NP230 which has a mounting area on the tailshaft housing, so it could be used with column or floor shift linkage.

all the 3 speeds 1969 and back did not have anywhere to mount the floor shift so they were column shift only which was more popular then

And the universal shifters were terrible back in the 60's. I don't remember selling a model specific Hurst shifter but just the Spark-o-matic universal ones. Sold a lot of Hurst 4 speeds though.