Mercury 3.0 liter lower unit question

[Cobra1998]

I have been trying to find out if the lower off of a 200 HP 3.0 will work on my 225 3.0. I have researched both serial numbers but that process is confusing to me. I wonder if someone could assist?

Failed unit is OG644113 (Mine). 1998 225 EFI 20"

Replacement is 1B778176. 2010 200 Opti 3.0 20"

Thanks for any help available.

Eric

[JOE54]

the newer engine uses a 13 spline driveshaft your engine shows to use a 8 pline driveshaft if it indeed has a 8 spline it will not work , does your engine have an 8 spline on top of driveshaft where it fits in crankshaft ???

[Cobra1998]

Thanks for the reply. I will be pulling it tomorrow afternoon and find out. Found water in it after the KYKX Tourney on the Pines.

I lived 13 miles from there, in Hallsville a few years back.

[EuropeanAM]

Definitely need to know how many splines YOUR driveshaft has.

You CANNOT use the gearcase from 1B778176, as that engine is an XL (25" shaft) model.

[Cobra1998]

It has thirteen splines. I resealed my original.

Thanks guys!!!