the tranny in the pic is a th350 lock-up unit. the bell housing bolt pattern fits a small block or a big block chevy. the electrical connector on the drivers side is the connector for the torque converter lock-up. the switch on the passenger side i don't know what it is. i have not seen one on a th350. the tailshaft should be the long tail shaft. torque converters are usually best if replaced. you can't really tell anything about a tranny without taking them apart. without that it is a crapshoot. lock-up units are heavier than the non lock-up units. the tranny in the pics can be used for the application you want to use it for, but most go with a non lock-up unit for performance applications. | 
