SEI SE216 Lower Unit 1.62:1 Alpha DriveshaftThe SEI 90-216-BS SE216 is an aftermarket replacement lower unit featuring a 1.62:1 gear ratio and Alpha driveshaft configuration. Installation requires the appropriate Mercury upper adapter shaft, which must be verified before ordering.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.Features1.62:1 gear ratioAlpha driveshaft configurationSEI part number: 90-216-BSUpper Adapter Shaft RequirementThis unit requires the appropriate Mercury upper adapter shaft. You must have the correct adapter shaft in hand before ordering. Confirm shaft compatibility with your engine application and existing gearcase before purchase.OE Replacement ReferencesSEI lists this unit as replacing the following OE part numbers:1623-822442A191623-822442A201623-822442A211623-822442A221623-822442A231623-822442A241623-822442A491623-822442A501623-822442T861623-822442T87Fitment and OrderingVerify your engine application, serial number, existing lower unit part number, gear ratio, and adapter shaft compatibility before ordering. Matching the gear ratio alone does not confirm fitment.