There were three ratios available for that year range for the C14 and C15 series (C10 1/2 ton):
3.73 standard (also available w/ posi)
3.07 "Max. economy"
4.11 w/ overdrive trans.
As to daily/highway driving suitability, what engine are you using? The 4.11 is what your '49 should have now (if original), so no advantage switching there. The 3.73 would be better, but many guys still prefer a higher ratio, especially if running the early 6-cyl. engine. The 3.07 would be best for highway, but may be more sluggish around town, and worse when hauling loads or towing.
Here\'s an opinion from another thread.
The width of the rear end is a consideration, also. Another alternative is a swap to an overdrive tranny.
There are many threads discussing rear gears and rear end/tranny swaps in these old trucks. Try a forum search.
