Another alternative with no results reported yet:
Powerglide with Gear Vendors as the tailshaft.
Ratios:
1st 1.82:1
1st + OD 1.42:1 (recovers 78%)
2nd 1.00:1 (recovers 71%)
O/D .778:1 (recovers 78%)
Overall range (1st to high gear) 2.34:1 (slightly taller than 904)
Use it with higher numerical axle: your desired ratio X 1.42 to get the same ratio in O/D

Advantages: very strong small package, 4 speeds with very tight RPM drops, easy to get spares.