MKS Performance VR6 2.9 upper timing chain tensioner bolt 

Thanks just what I needed to see.

Just for the record.. if you lightly compress the tensioner with your fingers or clamp and suck on the outlet where you put the pin it will decompress the tensioner. Save you accidentally sticking a pin inside and it snapping. PS. May get a taste of oil in your mouth 😂

but then the first rotations of the engine wont have chain tension?