Date Range filtering using Google Search Appliance crashing
So the drupal module uses curl to query the google search appliance, which means if your url is too long, you may run into issues. 

It would be better to send a range to the Google search appliance by altering the $query['gsa_query_params'], ether by using the required-fields or partial-fields.

However, google doesn't currently support ranges to be sent via these options. Hopefully they'll add that functionality, but if you can't wait indefinitely for them to add the functionality, you can get a bit hacky and get it to work.

So, the Google Search Appliance has a flag, "inmeta" which does allow you to create a integer range. The catch here is it can only be used in a query field. IE a search for 


  "John Doe AND inmeta:1901-1940"


What you could do though is use the GSA Drupal module. 

hook_google_appliance_query_alter (where your altering your queries to create your other filters) to add to your q string "AND inmeta:[range]". The issue here is that when you use this, drupal will display the full q string, with the inmeta field showing. Which might look strange for your users. You could save a copy of the q string before adding the range to your $query variable. Then, before displaying the page, but after the query has been executed, switch the query string back out.