1996 28 hp gear case compatibility with 1970 20 hp

[heypawpaw]

Looked at a 1996 28 spl long shaft and it has a split gear case that looks like my 1970 20 hp gear case. Are these interchangeable?

 

[racerone]

Have you looked at the spline on top of the driveshaft ??----You may find they are different.

 

[heypawpaw]

Thanks raceoner, I haven't looked, didn't want to invest in the 28 if not compatible.

 

[Chinewalker]

No, they are not. 28 uses heavier gears and bigger diameter driveshaft than the old 20hp unit.

 

[heypawpaw]

Thanks Chinewalker appreciate the help.