Anyone care to explain the benefit of head studs over head bolts? Thanks.

 

Studs torque more evenly than bolts because you're only turning the nut at the top of the stud, rather than turning an entire bolt...so you get a more accurate torque reading on your torque wrench and there's less likely to be a lot of variation between the studs.

As a result of that I believe studs are also said to have more clamping power.

 

ghunt is right on.

 

YOu can bottom out the studs too, whereas the bolts will always have to be unable to reach the bottom of the threaded hole in the block.