Help! Stall Converter fail to work

Larry you either got a bad converter or the splines aren't correct and not engaging. There are 2 different spling counts for the 904's but I don't deal with 904's enough to remember what they are. Since you have the converter out look down inside and count the splines on it and compare it to the old converter. If their the same count you got a bad converter. If their different they sent you the wrong one.