Lead assemblies with arrangements to confirm alignment between terminals and contacts

A lead assembly includes a lead or lead extension having terminals and a mechanical stop fixed to the lead or lead extension and located distally to the plurality of terminals. The lead assembly also includes a connector having a connector housing, a connector block disposed within the connector housing, a port defined at the distal surface of the connector housing, a lumen extending from the port for receiving a portion the lead or lead extension, and contacts disposed within the connector housing. The outer diameter of the mechanical stop is larger than the lumen diameter within the connector block to halt further insertion of the lead or lead extension into the connector housing. Additionally or alternatively, a visually distinctive marking can be applied to the lead or lead extension to indicate alignment between the terminals of the lead and the contacts of the connector.