My 2011 6.7l did the classic valve break and destroyed the head and cylinder. I bought a brand new short block and have been buying everything new to have a totally new Long block. I'm working on buying new heads now and am wondering if I should get o-ringed w/ hd springs or stock. The original engine I updated turbo and cp4 to 2015+ and it is tuned and deleted with multiple other upgrades. I live in the mountains and tow an 18' enclosed work trailer that is loaded down. I tow it everyday and getting to some of these mountain homes to work on have steep long curvy inclines. Would it benefit me to spend the xtra few hundred per head for the o-ringed and hd springs.

 

The 6.7 had 6 bolts per cylinder vs 4 that most engines have…this was done to prevent head gasket failure and that seems to work as head gasket failure is an unknown thing in the 6.7


the HD springs are usually for high revving engines which the 6.7 is not.

so my take would be no on both.

i would put the money into billet oil pump or upgrade the push rods to Molly.

 

Save your money and pass on the oring heads and purchase a S&S DCR hpfp instead.

 

I would go DCR too and just get stock parts with the revised valves and heads.

 

Thanks for all the input. I'm definitely going chromolly push rods. I wish I had known about the dcr hpfp, I've put less than a 1000 miles on an updated cp4 with a SPE dpk on it. Is there a model # that tells me it is the revised valves and heads or which model# not to get. Also I ordered 4 rocker arms on 1 side the same(LC3Z-6A585-F) but the other side I have 2 LC3Z-6A585-E and then 2 FC3Z-6A585C . The FC3Z were cheaper. Are those rocker arms the same and they just changed the sku # or do I need 2 more LC3Z-6A585-E.

 

Since you already spent the money on the CP4 pump, it would make more sense to get the River City Diesel CPX. This is an upgraded CP4 pump that bolts right in with no modifications. The lifters are pinned and there's room to grow built into the pump of you opt for larger injectors down the road. The DPK is also built into the pump, so should it for some reason grenade, it's self contained and won't contaminate the fuel system, tank, and fuel cooler.

https://rcdperf.com/products/2015-6-...an-bosch-cp4-2

Since your pump is in good condition, it's a buildable core and you won't have a CP4 pump sitting on your shelf.