want to swap blocks

[lstring]

i have a 1979 100 hp evinrude "1009983s" needs to be rebuilt. i also have a 1978 85 hp evinrude 85899c that does not. i looked up the part numbers and everything tells me that the blocks will interchange with the mid section but the drive shaft numbers are different,does this mean that the splines are different or something else?
please help
leon

 

[racerone]

The splines are the same.----------------The 79 crankshaft is different ( much heftier center bearing ) than the 78 - 85 HP.------------------------So the thing to check is the length of the driveshaft.

 

[lstring]

so the spline end of the 100 shaft would not fit in the 85 crank ?

 

[racerone]

The splines dimensions ( diameter and count )are the same !! ------------the length of the shaft may be different.------------as in it may bottom out in the crankshaft. ----------I think you can measure this to make sure.

 

[lstring]

thank you very much for the information.