A system for aligning a prosthetic head component with a prosthetic stem, the system comprising: a mounting plate comprising: a first major surface that is planar; a second major surface that is planar and opposing the first major surface; an adapter accommodation hole extending through from the first major surface to the second major surface; and sizing indicia located on the second major surface; a first fastener extending from the mounting plate; and an adapter coupling plate slidably engaged with the mounting plate, the adapter coupling plate comprising: a third major surface that is planar and facing in a direction of the first major surface; a fourth major surface that is planar and opposing the third major surface; an adapter coupling hole extending through from the third major surface to the fourth major surface, the adapter coupling hole surrounded by the adapter accommodation hole; and an indicator located on the fourth major surface to point to various portions of the sizing indicia as the adapter coupling plate slides against the mounting plate, wherein the adapter coupling plate is configured to slide against the mounting plate in a first linear direction parallel to the first, second, third, and fourth major surfaces (54, 56, 64,66). a mounting plate comprising: a first major surface that is planar; a second major surface that is planar and opposing the first major surface; an adapter accommodation hole extending through from the first major surface to the second major surface; and sizing indicia located on the second major surface; a first major surface that is planar; a second major surface that is planar and opposing the first major surface; an adapter accommodation hole extending through from the first major surface to the second major surface; and sizing indicia located on the second major surface; a first fastener extending from the mounting plate; and an adapter coupling plate slidably engaged with the mounting plate, the adapter coupling plate comprising: a third major surface that is planar and facing in a direction of the first major surface; a fourth major surface that is planar and opposing the third major surface; an adapter coupling hole extending through from the third major surface to the fourth major surface, the adapter coupling hole surrounded by the adapter accommodation hole; and an indicator located on the fourth major surface to point to various portions of the sizing indicia as the adapter coupling plate slides against the mounting plate, a third major surface that is planar and facing in a direction of the first major surface; a fourth major surface that is planar and opposing the third major surface; an adapter coupling hole extending through from the third major surface to the fourth major surface, the adapter coupling hole surrounded by the adapter accommodation hole; and an indicator located on the fourth major surface to point to various portions of the sizing indicia as the adapter coupling plate slides against the mounting plate, wherein the adapter coupling plate is configured to slide against the mounting plate in a first linear direction parallel to the first, second, third, and fourth major surfaces (54, 56, 64,66).