boostbandit1

Last year I built a heads cam motor for my truck (lifter failure) and when I was bolting everything up I wanted to add another ground.
Long story short I removed this bolt only to hear something (have no fn idea what) fall behind my firewall inside the cab under the dash.
Would anybody know wtf it would be? I've searched without anything pointing me in the right direction and I'm trying to figure out what it is bc it's making a "thud" sound when I hit bumps which is very annoying.
Truck is a 2005 silverado with the 5.3