scaling part of the object

 From:  ulisses
10268.1 
Hello,

I need to scale part of the object, where I have the dimensions.



I need to expand the object from 60 to 80 in the front part, without change the back of the object.

I tried the 1D scale, but it stretches the other part as well.
I tried to select some faces and move, no success.
Maybe cutting the object in half?

Tks.
Ulisses
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