[MSWhitehead]

if the armature is to big they sell new housings, brush kits, props, etc as well

True but the front part of the housing that is threaded to the shaft won't fit a bigger armature housing. By the time I bought all the new parts plus a new extended shaft, since you will more than likely screw up the composite threads taking it apart, I might as well just invest in a new bigger troller & sell the old one.

 

[MSWhitehead]

I think you can as long as the armature/housing diameter is the same as well as the overall length. I tried to upgrade my 70 to an 80 when I replaced the armature a couple years back but minn-kota said the 80 housing was a little bigger so no go.