1st off, the bellcrank setup was on the 55 2nd only, dropped in '56, not appropriate for your 57 .... not sure, but I suspect your OD trans may be a 55.2 version, and was adapted to fit the 57 linkage [which you have] - the early trans levers faced opposite ways, one up and one down, the 56+ levers both pointed down .... might be you just need to find the correct trans levers, but in either case, the shift box arm adjustment won't change
Bill