It seems like you're making your part multibody to change the length, then merging back in to one body.
I would just use a move face with translation after the revolve, which can then be changed or suppressed in different configurations.
I hope this helps.
I was hoping for a quick and dirty solution like after you make the move body feature, select it and a dimension will show on screen, but this doesn't appear to be the case with move body. What I have done is create a controlling sketch with a configured dimension that I would anchor the move body to. You wish to move it away a certain distance, instead move it to the endpoint of a line that equals your configured distance.
Expand the Body-Move/Copy1 feature in the tree, right-click on the Distance mate, and choose "Configure Feature" from the drop-down. You'll get a simplified design table, with a row for each configuration, and a column that will allow you to set the suppression state for each configuration. Click on the drop-down beside the feature name...
...and click on the box for D1.
That will add a column for the dimension value. Enter the desired value for each configuration and click Okay.
This method is described under #2 at How do I set a configuration specific dimension or value? . There's more information there about this table that you might like to review.