I am missing the drag link for my steering. Is there a way to measure which length is correct for my chassis? I don't know exactly what year the chassis is but it is probably a 1925 based on what another member here told me. It has the two hole quadrant and no side hole in the frame for the rear engine mount ears (TT frame). The only thing that has me unsure now is that I found a date on the front axle from 1926. The encyclopedia says that one size of drag link was used from 1919 through 1925 but changed in October 1925. What was changed to make the length of the drag link different?
Is your chassis on wheels and assembled? If it is, just set the wheels straight ahead, center the steering wheel halfway between full left and full right, and measure the distance between the ball on the pitman arm and the ball on the tie rod.
Here is an older thread talking about the different drag link lengths: