i have a thread over in the competition section but figured i would post it here also cause i might get a answer quicker and a more knowledgable answer cause everyone here runs this engine

i have a question i am wondering what the max boost that the factory headgaskets or aftermarket head gaskets will handle with just head studs, i know the gaskets are good to 40psi with factory bolts and at what pressure would i need to o ring the heads with the studs, have read alot on this and dont want to fire ring have heard alot of issues with sealing when cold, and i like the idea of o-ring cause it just seals the factory fire ring in the head gasket tighter.

the reason i am asking is i am thinking of building a compound turbo setup for my truck cause my current turbo is maxed out when running up to the 3800rpm mark and running around 40psi boost, i have set down and done a rough mapping on the compressor map and i am way off in the choke side of the map at the 3800 mark but at same boost and a lower rpm say 3000 i am starting to get on the border of the choke side, so i want to add a low pressure turbo to feed this so i am able to build power all the way to red line. i dont want to go to a larger single turbo cause i dont want to get a bunch of lag like the spool up of this turbo currently and i need that quick spool up do to towing.

 

I woudln't trust stock springs/studs over 40psi.
45 at the most.

Our heads are beefy compared to the Cummalots and the Durasmacks.

I dont honestly know of any guys fire-ringing PSD heads.

Cody's pull truck is in the 600-700 hp range.
The motor is damn near stock except for the supporting parts to get it there.
No girdle, no fire rings. upgraded studs and springs yada yada.
Thats it as far as I know.

I guess if yoru shooting for 1000 hp i'd ring it.

I'd think of a different turbo than going to a compound setup.
but thats my opinion.

 

Wop offers fire rings I believe. I'd do push rods and springs just to be safe. For the cost of both you will spend more pulling a head again or time to change push rods. Your on borrowed time pushing the motor now to 3800 on stock push rods. Iirc Wop was running trips or maybe quads on there rail car and never had head problems.

 

yea springs and push rods are next on my list to do just didnt have the money to do them this time around so from what i am assuming is 50-60 should be fine without o ring but probably at its limit

 

As long as your springs are up for the task and the studs were done right, you should be good for around 50-60psi. Once you get at or above that level, you need to pull the heads and do fire rings.

Lots of people do fire rings on the 7.3L, but not very many people o-ring them. I'm not sure why, but that's how it is.