the idea is that the studs go further down the thread in the block to increase the " grip " they are not stretch bolts so they will not stretch when put under high strain from a high boost engine ( preventing the head from lifting up ) they also help to align the head and keep the gasket still when fitting a new gasket..

a much more reliable set up and a must ( at the least ) on high boost engines. and are reusable..

or go for full WRC long studs that need machining the thread in the block
to prevent block cracking....