Chris I have a chart which does show a 4.03 1st gear for some '85 F-body applications. Ratios are 4.03/2.37/1.49/1.00/0.76 - these are the same ratios as the 2.5 4cyl S10, Also used by many AMC and Ford. This would make a good trans for a taller rear ratio like a 3.08 or 2.73, as your overall gearing in low gear would be close to 12. The only negative would be more the RPM loss at the 1/2 shift.