[Set] Assault Vest

 

This is a set I really like. With Sand Stream and the Assault Vest, Gigalith can take special attacks very well, even some super effective ones, and retaliate powerfully after. However, it has not recovery at all so getting a Wisher in the team should be a good idea. Also, as Gigalith can't set up Stealth Rock with the Assault Vest, so a teammate that can do it is recommanded. 

Variants

-Putting EVs in SpDef instead of Attack. Your Gigalith will be even more bulky and will still have a decent offensive presence. However, as it lacks recovery, I think investing in Attack is better.

-You can use moves such as Superpower, Body Press or Heavy Slam.