ARE these lower units interchangeable 1989 mercury 150 HP black max # 0B198511 on to a 1995 mecury 150 HP XRi 2.5 litre #0G201546 They look the same but 95 is completely disassembled so i can not put them side by side...my next step is to measure the distsnce of the spline on top of the drive shaft to the bottom of the motors ..with out the lower end on..any help or comments would be great appreciated .. fishing season is coming fast !