1997 Olds Bravada w/4.3 Vortec

I am in the middle of reinstalling the fuel line bracket next to the distributor and have lost the bolt and washer. I know it's a 10mm head, but don't know if the thread is metric orSAE. Any ideas, none of my 40 year collection of hardware fits.
Thanks.
Peter

 

If its a mm head its metric thread also. Dont know what size also

 

It's an M8x1.25 bolt about 3/4 inch long.