In my '38, I used a mid-eighties 4WD S-10 axle (the 4WD axles were wider than the 2WD axles) with 3.42 gears and 4" wide two-piece bolt-on 5 to six lug adapters and stock wheels with original size bias ply tires. It was just the right width.
I used the .72 overdrive T-5 with a stock rebuild 261 inline and was very happy with the pep in the old trucks step.
Do you know the overall width measurement with the adaptors? Seems like that would be too wide, but I guess not. I need to be around 59-60" total width, WMS to WMS.