Mopar Distributor Identification by Shaft Length
Filed under Mopar Engine
Measured from mounting surface to end of distributor shaft.
Mopar LA engine – 3 7/8″
Mopar B engine – 3.5″
Mopar RB engine – 4″
Chrysler 331/354 Hemi – 4.25″
Chrysler 392 Hemi – 4.5″
Dodge 241/260/270 Hemi – 3 7/8″
Dodge 315/325 Hemi – 4.25″
Desoto 276/291 Hemi – 4.00″
Take care when swapping distributors as the rotation is not always the same. That information will be added as it becomes available.
http://www.hotrodreference.com/1310/mopar-distributor-identification-by-shaft-length/