Hmmmmmmm............This ol' problem AGAIN! OK, if I understand your "10 to 4 position" to mean
slightly to the right of center, I
MAY have the mechanical reason for you, IF you used the '40 PITMAN arm. Refer to the pic below.
The Pitman arm on top is a '36, and the bottom one is a '40. If you look closely, the center to center distance between holes is greater on the '40 arm. Since the drag link (when viewed from above) tends to form a triangle shape of sorts by angling rearward, away from the tie rod at it's extreme left end (where it attaches to the Pitman arm), some strange geometry comes into play if you change Pitman arms (lengths). The '40 arm would place the left end of the Pitman arm closer to the tie rod ('cuz it's longer)...WITH THE STEERING BOX CENTERED. Using Pythagorean's theorem as a guideline to illustrate the dynamics of a RIGHT TRIANGLE (consider the tie rod and Pitman arm as the two shortest sides forming a right triangle), what's really happening with the '40 drag link is an example of the need to DECREASE the length of the hypotenuse. Your drag link is the hypotenuse in this theoretical right triangle. SOooooo..........if you did not initially adjust (SHORTEN) the length of your drag link after the '40 Pitman arm substitution, the "too-long" drag link (with the steering wheel straight ahead) will **** the wheels ever so slightly to the LEFT.........hence, your having to ever so slightly hold the steering wheel to the right......to go straight down the road! There ya have it in an otherwise perfect world. Yes, no? That's what happens when us damn hot rodders go screwin' with Henry's infinite wisdom. DD