Busboy

For some perhaps but the number of trucks with studs is probably less than 1%, the other 99% aren't using them and most of those never blow a head gasket. It all boils down to how you drive it.

Mike Holmen

Making sure that your head studs or bolts are tighten up to the required torque is a must. The stock cummins bolts (which I run on my 2010) has been retorqued to 135ft*lbs. My stock bolts moved at 125 ft*lbs.

Even the stock replacement cummins head bolts are nearly the same price as the ARP 2000's. The ARP 2000's are just slightly higher quality than the factory cummins bolts. We have been torque in up 12V head bolts to 135ft*lbs for years, and they take 60-70psi of boost with no issues.

I also found that my intake/exhaust valve lash on my 2010 was way out of spec. I'm currently running 10/20 thou on the intake/exhaust

Busboy

Nicely in the middle, 6-15 intake and 15- 30 exhaust. On the bolt or stud subject the convenience of the bolt over the stud plus the fact you already own them sold me on the bolts, like you say you just have to "maintain" them like every thing else including the valve lash. Unless going crazy with power I think the bolts are more than adequate.

Mike Holmen

Once you delete, you can adjust the valve's to 10/20 spec's. The extra lash is because how warm the engine gets during full reg cycles.

I even found a rocker adjuster loose on one 2010 truck.

redlineguy

How do you think I drove it that caused this?

Busboy

Well like Mike Holmen has said he has found head studs not torqued correctly which could be the problem, or perhaps working the engine too hard without it being fully warmed up. I have blown way more than my fair share of head gaskets in the past and it was always from over working them, now I just take it easy until the engine is fully warm and don't over do things, I only run mild with the mini max that seems plenty for my needs, for defuel I have boost set to 34, EGT 1200 or 1250 not sure, coolant 180F and even after the 180F I don't work it hard, I might tow another 15minutes after that before I do much of anything.

My point was that probably less than 1% use a tuner and most of those don't use head studs. Sure for some head studs are a must along with fire ringing the head if you are going to want lots of power but if you are going to run on mild, limit boost and EGT and let the engine warm up they are definitely not needed and if after that you do blow the head gasket there was something else wrong like the bolts were not at the correct torque.

Mike Holmen

I agree with you, but there could also be a tuning issue? What tune and how much timing do you run?

If I was going to push boost levels up I would install an 42thou oring instead of a true fire ring. Not to knock true fire rings, as they work well, they just don't hold-up for long term usage.

The Haisley fire ring kit (isn't a true fire ring), just installs a fat/thick oring into the head, that sits on top the 6.7 headgasket "firering". Which is a great idea, but there are a few more coolant holes in a 6.7L block vs. a 5.9L

When done right a MLS gasket will take lots of abuse. I've built one 6.7L engine that I had to deck 14thou of the surface just to true up. Fix that typical 5-10 thou waveness on the head. Use 625's head studs, you probably good for 60-80psi.

12valvewagon91

When I built the 360, and the 408 stroker in my demon, I studed the mains and the heads. The heads went in the block finger tight. HOSS there shold be either a hex head on the head side of the stud. The Cummins might need to be put in a touch tighter than finger tight, but the allen/hex head in the end makes for an easy install.

On a 6.7, can you just remove one at a time, and torque it down slightly to keep the head in place, then torque all them down in the sequence?

Just a little curious on that myself.

My lil small block stroker with indybrock aluminum heads, forged 4" crank, billet childs and alberts rods with 10.8 comp makes close to 515hp, and 545 lb ft. Going to have it on a wheel dyno this summer for some better carb tuneing, but with the studded top and bottom end, that lil girl is rock steady!

donato

I’m no expert but one of the difference between studs and bolts I’ve read is the different forces acting on them. Bolt will have a twisting force as well as a stretching force, as where studs will have only the stretching force acting on them. The stretching force plus the twisting force makes for a weaker fastener. A blown HG is the result of stretching the bolts or studs over time and a twisted-stretched bolt is more susceptible to stretch further or break than a properly torqued stud. Getting studs of a higher quality material will make the studs even less susceptible to stretching and the difference in the cost of the raw material will reflect in the cost of the finished product. Again I’m no expert and this is only what I’ve read so I won’t argue with you.