The 5/74 MPC lists the following: Panel Light Fiber Optic, 68-72 All A/F body, #6293310, guide ash tray light,
20” single wire.
However, GM makes modifications and running changes during the model year and maybe it was determined that a 28” cable was needed. M&H could be working off an original blueprint, and the MPC never updated and still reflects the original 20” spec. Not familiar with the 69 dash cluster but is it possible that the socket the cable attaches to should be in a lower position, though it has a 28” cable for a reason.
