3.6 turns for fast steering compared to 5.3 for standard. The boxes are the same. The longer length of the arm is what makes it "fast".
See
this.
This is always confusing...
The factory longer length arm deal is for
power steering fast ratio. This was
optional on 70 TA/AAR's, 71 340 cars, and
standard on 71 340 power steering cars built after March? of 1971. 70-71 E-body only on certain models/combinations. It's roughly equivalent to 12.7:1 ratio and it's 2.8 turns to 1.
The manual steering 16:1 fast ratio was done by the gearing in the box itself. Optional on 65? to 69 A-bodies only. It's 3.6 turns to 1
Modification-wise you can put a repro power steering arm with the appropriate output spline diameter on a manual steering box. Some of the aftermarket resellers like PST advertise this. On a std manual 24:1 box the net turns lock to lock will be 3.6 to 1.
Longer pitman arms interfere with all off the shelf A-body head-pipes for manifolds and headers except for Schumacher Tri-Y big block and Spitfire Tri-Y headers.
