727 vs. 904???

The 904 came out of a 72 Dart - the 727 came out of a late 70's - early 80's truck. Both attached to 318s. Both have been checked over and are in working order.

Everyone likes the 904, any concerns about the strenght of the 904 compared to the 727?

Please tell me a little more about the 904 consuming less power "it consumes less power"? I am leaning toward the 904, but still have some concerns?

Which converter to use? I have the /6 converter, the 904 converter and the 727 converter?

Which converter to use?? Why??

Thanks, Sam