We have been seeing more and more that standard arp studs and stock oem gaskets are failing... even after all the proper prep work, making sure block and heads are flat, etc...
I have my theories but it all boils down the the multi layered MLS gasket, the sealant compound around the fire ring, and the low tensile strength of the arp studs. Ask yourself why the 6.4 guys have less problems??? they have the same crappy 4 bolt per cylinder design, they use the same MLS gasket, but they seem to have much fewer problems. I think it comes down to better tensile strength of the thicker bolt they use that saves them, but they still fail.
I know everyone is going to jump on and say... but lots of guys have made big power on standard arp studs and OEM gaskets. Well I would venture to say that many of those guys eventually blew their gaskets or maybe don't drive them long enough to see a small leak. I would also venture to say that for every 5 guys who made descent power on standard arps and OEM gaskets... well 50 had repeat failures.
My truck recently started leaking. It only puked if I spent over an hour on the dyno testing. I attributed it to getting to hot and overfilling the degas. Well I eventually stuck a gauge on the truck and tested the psi of the degas bottle. Everything check out ok for normal driving, but if I got on it super hard the psi would go up about 2-3psi every run. Well after about 10 super hard runs my truck puked. My heads were not blown, just leaking. It would be hard to see a slight leak going down the track. You would probably only see it while going up a really long hill or if you spent all day on the dyno.
Another thing to think about is with a big vgt turbo and/or compound setup you are going to see super high cylinder pressures because of the large amounts of boost that you see at such low rpms along with the added back pressure/drive pressure. I believe that also adds to the people making big power and blowing gaskets. I would also venture to say that guys with large single non vgt turbos have less problems because they make their boost later in the rpm band when the flow rate of the motor can handle it better. 45psi at 2500rpms is way different than 45psi at 4000 rpms.
Some say over torquing the stand arp's help (like 230-250)
h-11s seemed to be a better option until they went out of business
ARP 625s are very expensive.
I like the new extreme stud option but I have seen very few reviews (i have set going in soon)
I also like the oring idea (not fire ring). I am going to be testing out that route also.
Stock??? 190,000 psi
normal ARP = 220,000 $450
extreme studs 240,000 $575
A1 H11 = 240,000 $750 (out of business)
aged ARP = 250,000 $1300
