that's a pic of the header lower bolt, shouldn't be there
for one thing that's an SAE 3/8-16 bolt (9/16 head) .....and the hole its in is metric M10x1.5
if you look at the bolt in the upper hole you'll see that its graded 9.8 ..that's a metric bolt (15mm head) and is correct for that spot
the bolt that was in the lower hole from factory had a 13mm head shouldered bolt M10x1.5 and the battery negative cable just goes under the bolt