904 vs 727

[1972-340challenger]

my car was originally a 318 car and has a 904. now its a 340 car with a 904. I just want to know what the diffrence is and if this trans will be strong enough.i know the 904s came on slat 6 and 318 cars so there a little weaker but i dont know how weak

[Chryco Psycho]

run it for a while & start looking fo rthe 727 , all the parrts in the 904 are lighter , it will fail eventually