Small block cam thrust plate bolt with oil hole

Just don't put the bolt in and use a dripper. Or just don't put the bolt in at all. The thrust plate holds the cam from the lifters pulling it back.

I never reuse the bolt it was a waist of time . None off the newer motors have them in. they all have drippers. The hole was to oil the chain. It gets better oil with no bolt.

The later magnums have chain tensioners.

actually two bolts are sufficient bottom left top right looking at the motor