Sterndrive Engineering Replacement Drive, Old Style R , MR , Alpha OneReplaces most Mercruiser Sterndrives 160/165 HP from 1967-1977Comes with a 8-1/8 old style input yokeShips in two boxesDoes NOT include install kit or anode kitUp to 300HP (SEI does not warranty applications over 300HP)Replaces Mercruiser Sterndrive 160 1967-1969 with trim and tiltReplaces Mercruiser Sterndrive 165 1970-1977 with trim and tiltItem is subject to a 20% restocking fee (Boat Covers, Bimini Tops, Outdrives, Drop Ship Items and Special Order Parts)!**Year, Serial Number, and Horsepower are required to order. Please contact us with this information after you place your order otherwise processing will be delayed.Sterndrive Engineering Model ChartRefer to Sterndrive Engineering’s model chart below to find your proper Mercruiser Sterndrive Replacement. These are typical applications; it is best to confirm your ratio by couting the teeth in the upper. Although great care was taken in the creation of this guide, its accuracy cannot be guaranteed.ModelYear RangeSerial RangeNotes (See Below)Standard RotationCounter Rotation120,1401967-19692062141-27919561,2,3,4,5,61.941.94 CR120,1401970-19822791957-62255762,4,5,61.941.94 CR1601967-19692065190-27634411,2,3,4,5,61.621.62 CR1651970-19772763442 and up2,4,5,61.621.62 CR225-S19743856268-42004994,5,61.471.47 CR2331975-197742005004,5,61.471.47 CR25019774791300-48987294,5,61.471.47 CR2601978-19824898730-62255764,5,61.471.47 CR4701976-19824208730-62255762,4,5,61.811.81 CR4851980-19824893835 and up2,4,5,61.811.81 CR8881971-19773106717 and up4,5,61.471.47 CR898/2281977-19824782330-6225764,5,61.471.47 CRR/MR/Alpha One1983-19906225577-OD4695856,7Notes:Unit has an 8 spline driveshaft on the lower unit. If your unit is original, you need to purchase a complete.Unit has a short yoke on the upper driveshaft. We refer to this as the Old Style***Applies to all inline 4 and inline six cylinder engines up until and including 1982***Unit must have trim and tilt for our Replacement to work. If it has two trim hoses going to each cylinder, it has trim and tilt.Unit has an eyelet on top cover. Replacement unit will not.Unit has a round cavitation plate on lower unit. Replacement unit will not.Unit may have an o-ring and/or a preload pin on lower unit driveshaft. The replacement will not.Gear Ratio must be confirmed. Chart below is typical applications, however there is no guarantee it is correct.To be safe it is best to remove the top cover and count the teeth on the upper gears.Engine ConfigurationHorsepowerGear RatioTooth CountStandard RotationCounter RotationInline 4 Cyl. 2.5L/3.0L120,1401.98/1.9420/241.941.94 CRInline 4 Cyl. 3.7L1701.84/1.8117/191.811.81 CRInline 6 Cyl.160/1651.65/1.6224/241.621.62 CRV6 4.3L185/1901.84/1.8117/191.811.81 CRV8 305 2 Barrel Carb.2001.65/1.6224/241.621.62 CRV8 305/350230/260