Santa Fe's CF-7's were a Cleburne rebuild of F - Units into a hood - type unit, more suitable for switching. The first units rebuilt retained most of the F - Unit cab including the low round roof and side windows. Later CF-7's were rebuilt using a Cleburne - designed, high angled - roof design cab. Some early CF-7's later received this new cab, while other early rebuilds left Santa Fe's roster for Amtrak or shortline railroads with the round roof intact.
While the railfan term " Topeka Cab " is often used to describe the angled - roof cab CF-7, Topeka cabs ( similar looking but different dimensions and height ) were only applied to GP-7 & GP-9 units rebuilt at Topeka Shops.