Yup, looks like am air cooled powerflight 2 speed, you'll need an adapter plate to put anything else on that motor. You will use the same adapter that the chrysler 331/354/392 hemis use for whatever transmission you want to put on it.

If you decide to use the powerflight, its got ratios of 1.72 and 1.00. You can add take offs to run lines up to a trans cooler (i would) the torque converter has fins on it that help cool it as well. Thats why the bellhousing has those mesh covers over the openings.

1956 315 hemi? a 57 325 hemi would likely have a torqueflight on it.