360 magnum into '66 Valiant

A built 904 or 998 will slip right in without any mods and handle the torque .
The a500 won’t fit without major tunnel changes and mount mods . Not a good choice for Overdrive .
How ever a GM th200r4 will slip in with minor mods to the mount . This is a better choice for the early a bodies that want 4speed automatic with overdrive .