have an 04 with massive blow by, an nv5600, 3.73's tows 14k lbs gn all the time on gravel roads and steep paved roads grades are 12%-26% does some highway time but spends an hour + using the exhaust brake contemplating retrofitting the new weeper system from Pacbrake when i do the rebuild if i can and keeping the elbow PBRX. keeping it mild but it operates at 3500-11000 ft in elevation most the time hence the thought of twins. for the last 100k miles the guy ran a smarty with the old 4.10 program and only mod was an HE351 on the truck only could run stage 5 becasue stage 7 would heat things up...... and did hence me buying the truck with a couple of burned up pistons, coolant in the oil and heavy cylinder knock.


Obviously i'll be running a SB springer hub dual disc setup in this one




contemplating 2 options

pull motor and do a simple rebuild using

480 QSB pistons
cam
INT. 181° / EXH. 210° 106 LSA
INT .280
EXH.307
mild ported head
girdle
and a set of small twins ported WG HE351/ S400
keep PBRX exhaust brake fab u remaineder of down pipe to secondary
ARP rod bolts / studs
valve springs and balanced engine assembly



Do something with the Free stripped 6.7 long block i have sitting in the garage, about 40k miles on it and really nothing wrong other than it was in a repo truck that had most engine parts already stripped.

Suggestions welcome, willing to look at coating the pistons or swapping other pistons but not sure thats necessary. but the option of a 12v rod swap means i'll pull it down some and that would be the time to do something if anything other than a balance job
5.9L cam with added displacement should be pretty mild or is the duration on exhaust going to kill the 1000 rpm to 1500 rpm power band which is where on the gravel roads lugging around corners witha load really counts.
188/220 108LSA
INT: .310" Lift
EXH: .320" Lift
mild ported head
girdle
12v rods since i have em
new factory SS 03/04 injectors with some 20% increase in flow tips
HE351 ported WG/S400
keep PBRX
ARP rod bolts / studs
valve springs and balanced engine assembly

since the 6.7 and 305/555 bowls are similar slipping a mildly built 6.7 long block in place of the 5.9 seemed an option worth considering. I'd be using all of the 2003/2004 electronics and the 2003/2004 305/555 style injectors especially since none of the emissions issues would be retained and everything would be run off of the 5.9 programming, including 5.9 exhaust manifold, 5.9 intake etc. so essentially nothothing 6.7 other than block, pistons, full head and crank.


looking for a solid reliable low end torque combo and thought using the 6.7 .... no substitute for displacement would be fun to consider. i think with small twins, a solid mid / low end cam capitalizing on high lift and moderate to shorter durations i should be able to keep mileage up and increase off the line grunt without too much effort. might not have teh peak numbers its capible of but should be a solid and reliable runner with alot of grunt

Cam is going to be key to this build. snap off the line or in this case lugging around corners is going to be everything when towing the trailer having to shift on a steep grade and switch back can kill momentum. if you've ever done it you know 3rd gear in low range and having to drop to second is the difference between tires possibly spinning and keeping things rolling


THOUGHTS?

 

Keep the 5.9. Too many questions about the longevity of a 6.7.

 

???
Not sure i got what you were getting at..... im not selling the 04 to buy an 07+ truck im talking about an engine rebuild or using the 6.7 long block since its clean and doesnt need any major machine worknor a full engine kit.

if im using 12v rods in the 6.7 build, using the 6.7 head, 6.7 block, 6.7 crank and 6.7 pistons (possibly coated) then everything else will be 5.9 including injectors and the lack of any emissions system .....since i'll be slipping it under the hood of the 04.... what exactly am i going to be facing as a reliability issue with the 6.7 long block or what should i be looking for?

Im willing to do the 5.9 build though i think with machine work, and a full engine kit it will be more money than building and upgrading the 6.7. definately all ears

 

My question would be what are you going to do electronic wise to get a 6.7 to run in place of the 5.9? What trans are you bolting up to the 6.7? Is their even a kit out to do so?

Just wondering.

 

I don't think you will see a big difference in reliability between a 6.7 and 5.9 you can use most of the 5.9 parts and no-one will tell its a 6.7 all the electronics will come from the 5.9 your only using the block and both were built with a 350k service life expectancy. removing all the smog trash from the 6.7 can only help I would stuff the 6.7 in the 04 if i had one sitting around collecting dust. my.04

 

The 6.7 swap has been done before. You will use the 5.9 electronics. Can't remember all the details. I know there is an issue with the 5.9 injectors in the 6.7 head. They won't seal up. Do a search on CompD.


12v rods and 6.7 rods are differnet lengths. You will need to buy cunninghams, etc. Get ready for the $3,000 bucks for those.

 

ah so i was mis informed, thought i had read a few years back that 12v rods could be swapped in. i even thought id caught the specs as being the same and that the difference betweent he two engines was in bore and crank .....but i gues i was smoking something and

added some links for where ive come up with the rod thought:
http://competitiondiesel.com/forums/...d.php?t=117492
http://www.dieselbombers.com/6-7l-pe...rged-rods.html

i'll keep digging using the 6.7 interests me for the extra displacement but.... we'll see


thanks for the info, just getting into the meat and potatoes of this idea.

Added a link to thread you suggested:
http://competitiondiesel.com/forums/...d.php?t=113414

 

So time has come this idea keeps floating around, i ended up picking up a 5.9 motor for the 04 truck and selling it before i ever got around to a build. but now what happened recently is a couple fo injectors on my 03 took a dump, so a set of injectors in needed as well as some other motor repairs.

then this morning a friend of mine passed on a deal for a 2012 6.7L complete engine that has 25k miles on it complete for $3900.....


the way i see it
keep the 200k mile + 2003 engine in there
new EDM don M injectors $2700 rebuilt
Cam
any HG or head work puts this project into the 4k-5k range real quick and im still using a 250k mile motor and all of the original 200k mile components. not a big deal as it's a swiss watch but it also could be pulled and slipped under my work bench, freshened up later awaiting the next project. pulling and reinstalling a motor is a cake walk so thats not a concern




Use the 2012 engine start out with a $3900 investment but its a fresh motor.

Strip engine of near everything sell turbo and few other odds and ends
Send injectors off for some 60hp +/- tips $1300 - do the solenoids need to be changed due to a lower voltage on the 5.9?

use the 6.7 larger rail, new CP3 and lines
use the 6.7L's alternator, AC compressor
install the 5.9's wiring, sensors, return lines, and computer
isntall a very healthy higher lift & longer duration towing cam
run the HE351 turbo and ATS manifold for the time being until i can afford small twins or a small S300 if i'll ever even need them.

with added displacement cam should be pretty mild or is the duration on exhaust going to kill the 1000 rpm to 1500 rpm power band which is where on the gravel roads lugging around corners witha load really counts.
witht eh 6.7L it would seem that the added displacement would provide quicker spool up and better pre-spool grunt
188/220 108LSA
INT: .310" Lift
EXH: .320" Lift
girdle
Run the nearly new stock 6.7 injectors and send them in for some tips?
HE351 ported WG
keep PBRX
ARP rod bolts / studs
valve springs and balanced engine assembly




the way i see it the 6.7 gives me a very fresh motor to start with, 20% more displacement helps with low end dirt road driving where boost is non existant, though my 5.9 rarely struggles. i have heard that changing out the piston coolers to earlier all metal ones is worthwile upgrade. otherwise sure some 5.9 rods would be nice but in a rig destined to stay in the 400hp/800 range and focused on mileage and low end power whats the point. anyways i'll have the 5.9l still under my bench ready for a freshening up if necessary if the 6.7 does go boom.


Are the 6.7's really having lots of HG issues with twins etc? are there piston or rod issues that are verifiable what other mecanical 6.7 issues are there would or wouldnt be an issue since this is going into a non-emissions 03 5.9 truck with two injection events? the idea is still intreging to me.