Transmission
Each Mopar engine family has its own unique bell-housing bolt pattern.  Big-block automatic choices come down to only the large 727 TorqueFlite.  The quick way to visually ID a big-block tranny (left) is to look for the four 1/4-inch holes in the bottom of the housing that retain the dust cover (arrows).  Small-block units (right) have only two 1/4-inch holes (arrows).

Nearly any automatic-equipped A-body, except 340 and big-block cars, will have the small 904 TorqueFlight (right).  It's shorter than the 727, so a new or shortened driveshaft will be required.

The Schumacher mounts are designed to line the engine up so that the trans bolts into its stock location, which it did.  A-body transmission crossmembers are all the same, whether 904, 727, or four-speed.

The slip yoke on a 727 has a larger diameter than the 904 version, so it will also have to be changed.  The large yoke is available with either a large or small U-joint (7260 or 7290 series; small 7260 series shown here), but a large-joint shaft should be considered mandatory in a high-horsepower application.

Unless it's converted to a full-manual valve body, the TorqueFlite transmission needs a functional kickdown linkage to operate properly.  Tight firewall clearance rules out the common one-piece linkage (left).  Somewhat harder to find, the factory three-piece linkage (right) does fit.  Save yourself the hassle and get a cable kickdown setup from Lokar, which eliminates this Rube Goldberg contraption.

Transmission installation with the engine and headers in place presented no problems.  It just lifted up and bolted in.