SEI SE205 Mercury Outboard Lower Unit 2.33:1, 25" ShaftThe SEI SE205 is an aftermarket replacement lower unit for select Mercury outboards. Each version features a 2.33:1 gear ratio and a 25" driveshaft. Choose the two-stroke, DFI, four-stroke, or four-stroke 4060 HP BigFoot application that matches your engine and existing lower unit.This item is subject to a 20% restocking fee.Year, serial number, and horsepower are required to process your order. Please contact us with this information after placing your order. Processing will be delayed until this information is received.Available Applications Two-Stroke 90-205-B25: For select two-stroke applications. Primary OEM reference: 1667-9011J23.; DFI 90-205-B25D: For select direct fuel injection applications. OEM reference: 1667-9011J39.; Four-Stroke 90-205-B25F: For select four-stroke applications. OEM reference: 1667-9011J31.; Four-Stroke 4060 HP BigFoot 90-205-B25S: For select 4060 HP four-stroke BigFoot applications. OEM reference: 1667-9011J41.; Additional Two-Stroke Replacement ReferencesSEI lists the 90-205-B25 as replacing 1667-9011A13, 1667-9011A14, 1667-9011A60, 1667-9011A61, 1667-9011A78, 1667-9011A79, 1667-9011G34, 1667-9011G37, 1667-9011J23, 1667-9011J24, and 1667-9011J27.Fitment and OrderingMatching the gear ratio and shaft length alone does not confirm compatibility. Verify your engine application, serial number, and existing lower unit part number before selecting a version. The BigFoot option is specifically for compatible BigFoot gearcase applications.