Max boost for stock head gasket and arp2000 (425's)
 

What's the max boost can a stock head gasket hold with arp 425 head studs? And is there a better head gasket out there without using fire ring or o rings?

There really is no magical number. I would only use a Genuine Cummins Gasket.

Luke

So with the mods in my sig do you think it would be ok to put the cummins head gasket back in without o rings

not with the compounds. you are running risky. def limit boost from the big charger maybe 50-60psi total. i personally wouldn't push much harder than that.

It was set on 60 but going to set it at 50 when the head work is finished tomorrow.

is it a ported head? if so it will flow better and i would run a bit more boost.

What does ported mean? The head is being resurfaced and cleaned tomorrow if that is what you mean.

LOL... that is not what i mean. 50-60 and a good tight seal should last you a good while. if you drive it sensibly.

I know I'm stupid mechanically speaking. What does ported mean?

A ported head will flow more and make more power at lower boost because it is moving more air. This is assuming you have the ful o make more power. Boost alone does NOT make power if it isn't at the smoke point.
I ran 55 lbs boost with my 02 and compounds with stock gasket and over torqued stock head bolts.

ported means that the head has had the intake and/or exhaust ports opened up so that the air coming in and going out moves more freely. usually the ports are smaller on the head than on the intake/exhaust manifold and they are opened up to be about the same size.

A ported head will flow more but you also risk port velocity for port volume and WILL make your turbo lag until you tune it to run with the lower drive pressure ... but that being said too much drive pressure can be harmful and will cause high EGT's as well .. its a fine balance ... I would leave the head alone and work on other aspects of your build..:tu: