identifying 4 speed automatic

Generally, start with basics. Is it 904 or 727 based? Google photos. Is it RH (hydraulic) or electronic (RE) Look for a multipin connector facing vertically up, behind the shifter lever. "About 8?" pins is electronic, 3 hydraulic. There should be numbers stamped on the pan rail, you should be able to search those

Also make sure you don't have a Jeep one, which normally has the starter on the passenger side.