What year did they change back to the 5/10 bolt pattern? All of the 67-72 medium duty trucks I have seen but one were 5/10. Only seen 1 with the 6 lug pattern and the rest were daytons.
I should have said 6000/60 series trucks had the 6-lug at least through the TF series.
I do know the 5/10 lug were used into at least the early 1970's on the 40 and some 50 series trucks (some 50 series trucks in the late 60's used the 6-lug), but the 60 series and up used the bigger bolt circle 10 lug or Daytons.
Mike B
