Ive read alot of the searched topics, but yet stil havtn found my answer. After head studding the 7.3 and better head gaskets what kind of boost numbers can the motors handle ? Ive found multiple suppliers for the 6.9 arp studs why not the 7.3 ? will they work on both motors ? also has anyone ever ran twins on these ? I have some extra time on my hands and might try putting up some big numbers for our IDI people

 

not sure why nobody makes studs for the 7.3 i know you can have them machined though.as far as safe higher boost levels you can rung up to around 15psi safely with studs i believe and more if ou drop the compression.newer trucks hae lower compression thats why they can run higher boost,but lowering compression in these can cause starting problems especially in cold weather.as far as running twin turbos i see no need to really do that because you will never be able to safely run "higher" boost with these motors.can it be done?yes im sure it can with some creative fabbing ,bit the only thing you will really get it the ability to say you have twins.im sure others will chime in on this too

 

The IDI was designed as a NA engine.

If you spend the dollars for 7.3 studs, you can run somewhere around 22 PSI before you will blow the intake manifold/valley pan gasket and let boost into the cooling system.

Can't remember which stud they were using, but there is an ARP stud that will work, you just have to cut some length off.
There was a supplier making 7.3 studs, but the price was close to 1000 dollars for a set.

In all reality, more than 20 PSI on either the 6.9 or 7.3 opens several other cans of worms for you to deal with.

Yes, there are ways around each of them, it only takes time and money for each fix.

 

IIRC the 7.3 heads have blocked coolant passages unlike the 6.9 your refering to Dave. One less worry.

 

Maybe, those look like freeze plugs blocking the coolant passage.

How much pressure you think they can hold?
Coolant pressure should never be over 14 PSI.

Besides, even if the boost can't get into the cooling system, it is still a problem if it is leaking.

I may have been leaking to the outside of the engine as well, but what showed up in the cooling system was more evident.
When the coolant starts blowing out of the recovery jug, you know you have a problem as soon as it hits the exhaust manifold.

And I can deal with those coolant passages a lot easier than I can the thin cylinder walls on a 7.3 block.

Been there, did that, several times.