This HG topic keeps coming up and it always ends up being argued about which is worse,,,drive pressure or cylinder pressure .....
Both are related to the HG failures but i think the repeated failures are from guys not getting their head checked or surfaced correct.
I blew a HG with all stock OEM emissions crap still on the truck with my Smarty on sw#3 all default and never seen over 30 or 32 PSI of boost. I cant say what the DP was because at the time , i didnt have a DP gauge...

I think these 6.7s come from the factory with very poor head specs. Meaning, they are just good enough to keep the HG in place IF, you are running stock tuning.
The second we up the HP, these poor head tolerances show us what our coolant looks like all over our engine bays...

I had my head decked and went back in with the OEM HG. I installed a BOD EWG and i have ARPs in the box on my workbench( too lazy or busy to install now) I havent been running hard enough to worry about the HG because my clutch is gone. I have a new Valair in the shop, ( next to the ARPs ) same story with the clutch as the ARPs....HAHA

I have been seeing a few posts about a new copper HG from Lazersmith, I hope this one is gonna work for us 6.7 guys.

 

My head was checked and decked then checked again by me before the last install I had everything within .003 when we went together with it and it blew again in 6 months but I do like to drive with a lead foot too.

 

This is the direction that I am going to head.

I talked to LazarSmith. Their HG is made to order and it takes 1-3 weeks depending on how their shop is loaded. They cost $325, that is just the HG. They stated that the head does not require quite the finish that is required for the MLS (Cummins) gasket for sealing. They talked about the water and steam ports around the cylinders being closer to the rim of the cylinder that causes more frequent failures due to the Viton on the MLS yielding due to vibration and the head lifting.

Talking to ARP, they state that they have many folks running 80 psi boost with their 2000 model studs. These studs have 220,000 psi tensile strength They are torqued to 125 ftlbs, thus giving you far greater clamping power of the head to the block. I bought these at $420 with free shipping. Their 625 studs are rated at 260,000 psi tensile, at the cost roughly $1200. They told me for my application it was money poorly spent for the 625's.

I only have EGR bypassed, H&H mini @120hp, AFE cold air and 5" straight pipe. I am not planning on going any further.

I might consider a 66 turbo later if I can convince myself that it will help in EGT's and not raise head pressure. The cost is also prohibitive at present.

 

Thanks for the update, keep us posted.

 

jpthomso-- you will love the hg are you going to oring it or just do the gasket? mines still holding great i have did a couple hard boost but not long and one 10hr pull to new mexico no issues im 100% happy with the work and gasket huge thanks to lazar smith

 

Awesome