'98 TJ Engine Block Ground - G105 size

Hello,

I'm repairing a '98 Jeep Wrangler TJ, 2.5 liter engine with automatic transmission. I found a disconnected negative battery cable that I believe is supposed to ground to the engine block at location G105. This is right above the oil filter on the bottom, right-side of the engine block. Looks like the G105 bolt is missing, and I need to replace it.

Any idea what size bolt that will be? I checked the FSM, but it doesn't have that detail.