hhott71 said:SBC or BBC don't need head studs because they have at least 5 bolts around a cylinder to provide clamping force.
A N/A engine should never need them.
Most mild blown or no2 won't either.
When you start pushing the limits, studs are advisable in any application.
+1Bikefixr said:Any force on the bolt goes in two directions--vertically from the bolt being tightened into the block and in a twisting motion from the top of the bolt being twisted into the top of the block. Since studs use two different parts, the force is distributed between them, thus reducing it on both of them.
Also, studs have the threads rolled into the shank, this compresses the metal and keeps the grain of the metal in tact. Bolts usually have threads cut into them, removing metal and cutting through the grain.
Studs often have more thread engagement because they are screwed all the way down whereas a bolt is usually shorter than the hole it is screwed into.
Studs pose less wear and fatigue to the threads. they go in finger-tight one time whereas bots go in and out as often as needed, and as you torque the bolt down, it causes a lot of wear to the threads as the bolt pulls up into the thread grooves.
Studs ease assembly on some engines. I always use them on the main caps.
Studs of a given strength are less $ than a bolt. You can get cold-rolled forged bolts of very high strength, but they cost more than the studs will.