most places say studs over 45 psi, and fire ring/ o ring at boosts over 60-65. if i remember how they classify it, fire rings are cut in the head, o rings are cut in the block. and on fire rings the head gasket is modified and the original ring is removed from it and a mild steel ring that fits the groove in the head replaces it. if you are going for really high boost levels over 125 i would say you should have both the head and block cut. this way in theory if the head does lift any the ring cant shift or blow out of place. i read an article recently that the owner of BD diesel wrote stating that just to prove his point he built a cummins that produced so really high boost numbers on a stock gasket and stock head bolts. now how long it would last is a good question, but he did do it and stated the truck had roughly 10,000 miles on it on that setup. you would be fine with a stock cummins gasket and studs. i only fire ringed mine for longevity. i ran 65-75psi before i fire ringed it. on studs and a stock gasket and never blew one.

so the stock head already has a groove in it. you just gota have a oring to fit the groove made and modify the gasket? thats what i got from that. am i incorrect?

no you have to get that groove machined in

my head was o-ringed 2 years ago and been holding 85psi down the track. I would say it's something do once you upgrade the turbo along with studs. there is nothing wrong with saving up and when the gasket goes do it then.

how about retorquing, how often for o-ring vs. firering? just looking for the best option for me, i don't want to retorque every service lol.

BaditsDiesel is incorrect...
O-RINGS are cut into the HEAD only. It STILL uses a stock head gasket. The O-ring crushes down REALLY hard on the STOCK head gaskets compression/fire ring (the metal o-ring built into all head gaskets.

FIRE-RINGS do NOT use the stock head gaskets compression/fire ring. It is REMOVED and there is a ring pressed into the head that fits in a groove cut into the block. THIS ring becomes the holder of ULTIMATE pressure because it fits in both grooves.

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ASMXB24 - You should at LEAST stud your head!! I wouldnt o-ring it unless you blow the stock gasket. But you should be ok! I only did it because my head ALREADY blew its gasket AND I am going to get twins and want to be SAFE!

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AROBERTSON - No the stock head does NOT have a groove cut in it. Part of the BIG $$ of having o-rings done is the perfect groove they cut in the head. Its cut into the head in a perfect circle they then press in a wire that fits TIGHT in that groove. That smashes the stock head gaskets fire/compression ring as stated above.

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TurboStang - You should not have to re-torque once the initial re-torque sequence is done... A few times perhaps... You do this to make sure the stock gaskets fire ring is crushed properly and seated TIGHT

im not so sure i agree with your deffinitions. everyone i deal with II, scheid, haisleys, all call O-ringing a groove in the block. fire ringing is in the head. but fire ringing can be done in both head and block for a better hold. cause my head is fire ringed and its only cut in the head. and uses the modifiyed gasket.

Here is pure diesel powers description, the engine shop that did mine shares the same terminology... Maybe its just a PER SHOP description...

Fire Ring versus O Ring Cylinder Head Dodge Cummins Diesel

I dont really know, i would love to know the official description

so to o-ring you have to pull the block out and take it to the shop? i don't want to go to that length lol. i will more than likely be pulling my head this summer to do some port work on it so i figured while it was off i would go ahead and do this stuff to it. and im not too familiar with it yet lol. so if i am gathering the info right the firering is in the head or head block combo, and o-ring is in the block only? i read on another forum that firerings have to be torqued down much more often than o-ring? to firering you have to get a modified gasket but o-ring has just a metel wire that goes into the groove and uses the stock head gasket?sorry not trying to steal the thread just want some info:tu: