A999 tranny same as 904?

The various Torqueflites had the same internal ratios, despite their other differences. Until 1980, they were relatively narrow (see Tom Hand's detailed article); in and after 1980, a wide-ratio gearset was introduced and used in most of the 998 and 999 transmissions. This ratio was 2.54 in first, 1.54 in second, and (as with the earlier Torqueflites) 1.00 in third. This gearset, which uses a welded-steel planet cage, is noisier and less durable than the original-ratio gearset with its machined-aluminum planet cage, but the lower first and second gears helped cope with the tall rear axle ratios needed for gas mileage.

http://www.allpar.com/mopar/torqueflite.html

i thought eveyone says the steel planetaries are stronger then the aluminum ones....