Mercury Merc 25SS gear case.  This case has 14.4" drive shaft meaured from the top of the case to the end of the shaft. We have not rebuilt this gearcase but it turns over very smoothly and shows very little wear on the mating surface, not very much wear is evident on this unmolested gear case. Has 16:21 gear ratio, single inlet.  Nice prop shaft, cone nut and excellent gear case.