904 small block trans

What's it going behind?? I have 3 early A body transmissions that were behind Commando 273's! They have the 4 gear cluster and the front and rear pump, but the spline count is for the early torque converter! I think that can be worked around by any converter company if you just give me your details!! Thought I'd throw them out there, since I'm close by!!
I want to replace the 727 in my 65 Dart for couple reasons. Weight for one, and clearance for a shield. In case things go kaplowie, wifey keeps her foot.

Worst case scenario I do have another 727 and could move the trans tunnel up. I do like the fact 904s are about 40pounds lighter