Using paths should help you with this, here's an example API call:
So all you have to do is pass in a list of addresses (you would have to pass in those with matching street names yourself) and you can have a highlighted block.
To keep the shape more regular you may want to use Geocoding to get latitudes and longitudes, work out the lower left and right corner of the best-fit rectangle and plot a path around it's four corners instead.
API doc here: https://developers.google.com/maps/documentation/staticmaps/?csw=1#ImplicitPositioning
You can specify multiple paths to cover all of your blocks, as explained here : https://groups.google.com/forum/#!topic/google-maps-api/WAb556SoApw