max boost on head studs alone

[1973dieselhighboy]

i have a question i am wondering what the max boost that the factory headgaskets or aftermarket head gaskets will handle with just head studs. engine is a 96 7.3di all mods are in sig, at what pressure would i need to o ring the heads, have read alot on this and dont want to fire ring have heard alot of issues with sealing when cold, and i like the idea of o-ring cause it just seals the factory fire ring in the head gasket tighter. the reason i am asking is i am thinking of building a compound turbo setup for my truck cause my current turbo is maxed out when running up to the 3800rpm mark and running around 40psi boost, i have set down and done a rough mapping on the compressor map and i am way off in the choke side of the map at the 3800 mark but at same boost and a lower rpm say 3000 i am starting to get on the border of the choke side, so i want to add a low pressure turbo to feed this so i am able to build power all the way to red line.

[magicsac1366]

with what i've seen, head studs are required if your at or above 40psi. i think with the studs, and maybe some nice gaskets you should be good if you're staying around 40 psi.

[joeyd61]

S468 turbo,stock head gaskets, arp head studs,comp 910 springs w/30ths shims---hitting 50 psi boost..