1967 front seats

Can someone tell me if there is suppose to be some kind of spacer mounted under the front seat tracks? My seats slide fine out of the car, but when I bolt them in, they will not adjust forward or back as if they are jammed. As of now there is no carpet installed...
 
There are 'spacers', in a way, but their purpose is to prevent the track catching on the carpet, which you don't have.

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