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Grisley1958

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A little about me:
I'm 63 years old and work full time as a maintenance supervisor at a rest home.
I'm married with two grown boys and 5 grandkids
Live in rust belt (Western N.Y.)
Have done all my own mechanical repairs and most body work all of my life.
Have never purchased a new vehicle
I found some good information on this site for a truck I'm working on. 1994 GMC K2500 ECLB. Bought it last year, came from Oregon with no rust. 454, 4L80E which was bad. Threw in another 4L80 that I had to see how well the rest of the truck was. Truck was bought to do a 12 valve conversion which I acquired from replacing a 6.5 engine in a 1995 K1500 for a guy and this 1997 12 valve with NV4500 and transfer case was my payment. Well the 4L80 lasted a year, so on with the conversion! I stripped the truck down to the frame, bought a set of motor mounts from Jonesy's ( mainly to save me a lot of figuring ) and am just about ready to drop the engine in. While looking for information about that project, I heard about someone who had put Duramax brakes on a GMT400, which is how I happened to find posts on here about it. I just purchased front knuckles along with lower control arms, rotors and calipers from a 2001 2500HD. Everything is rusty (I live in western New York) but the cast parts are going to clean up nicely! Paid $100 for everything which I'm sure is a great deal considering the core value on the calipers. Found a lot of useful information on here but have heard some conflicting opinions on the tie rods. I have read that they need to be reamed for the older tie rods to fit and I've read that they need a bushing to use the old tie rod ends. I also saw where someone used the ES409 ends but not sure exactly if they fit the newer knuckles and then the original sleeves or not. Having the lower control arms (which I've read on here will work) will take care of the lower and I've ordered a reamer to do the top. Looks like my 16" wheels will fit over the new setup which is good, I'm getting excited about this project!
I love the GMT400 trucks, I have 4 at present that are licensed and parts enough to build a couple more.
1988 GMC 1500 ECSB 350, 700R4
1994 GMC K2500 ECLB (Current project)
1995 Chevy C2500 6.5 4L80E
1998 K1500 ECSB 350 4L60E
Parts :
1998 K1500 RCLB frame (rust free) 21,000 miles
1992 Yukon with a 1993 Cummins with a 47RH stuffed in it. (bought it unfinished and not running but runs now)
1994 K3500 DRW RCLB frame ( I welded a rear section from another DRW frame because it had been wrecked)
Lots of projects too little time!
 
Welcome!

There's a few of us here from the rust belt of western NY. Sure wish the DEC would shut down the salt operations for good and stop eating our vehicles alive.

Sounds like you came across the brake upgrades thread. I hope to do the GMT800 upgrade myself sometime. It's my understanding that you need to ream out the upper and lower knuckles to be able to use the GMT400 ball joints as those are larger which allows you to keep your existing upper and lower control arms. And the ES409 will fit the new knuckle but still thread into the old tie rod sleeve.

your Yukon with the cummins sounds interesting, is that a 4BT or 6BT? I've always wanted a 2 door yukon/tahoe/blazer with a 6.5 in it, would love to build a custom one one day with a 5 speed in it to boot 🤘
 
Thanks everybody for the warm welcome!
In my brake conversion I'm using the lower control arms from the 2001 (which I hear will fit) and from what I've read the originals will not let the truck steer as sharp. Good to hear about the ES409 tie rod fitting!
The Yukon has a 5.9 in it, the truck is rusty. Has a 6" lift kit with a 2" body lift.
I've owned several 6.5 Diesel trucks and have had great luck with them. Both my boys have ones I bought, one has 400,000 on it and still runs great but hit a deer and then a tree and totaled the truck.
My first 6.5 was a 1994 cab and chassis that I made into a dually pickup, I fabricated my own CAC for it, mounted at an angle below the radiator support and it worked great but the truck was only 2WD and worthless off pavement so that engine got put in the truck where I got the Cummins, Truck was getting pretty rusty anyway.
Beautiful day here after a good frost last night!
Trying to get some outside things finished up before the snow flies.
 
@Grisley1958 ...Your out towards Irving..old stomping grounds..lol. used to live at the cattaraugus reservation.
Actually no I haven't thought of that. Honestly not sure what a after cooler does...can you explain?.
My rig was a beast when I got her...then I made the mistake of letting a idiot wrench on it...had problems with it ever since...
 
After cooler or charge air cooler is when you take the pressurized air from your turbo and before it is goes into the intake you run it through something to cool the air. The pressurised intake air can be very hot!, especially with the inefficient turbos that GM used. Air or water can be used, I chose air. On mine once I plumbed it in I used a remote oven thermometer going in. And out of the cooler. I saw temps as high as 250 degrees when working the truck, but the. Outlet side was always whatever the ambient temperature outside was. It helps you keep from overheating or melting down pistons when you are working hard. Mine was mounted at an angle under the radiator support, never had any issues with it. When I built mine it cost about $300 but now would probably be around $500. Let's face it 250 degree air before combustion is a recipe for engine failure.
This is my opinion on the 6.5 engines. They are great as long as the haven't been rebuilt. These engines had hand fitted main bearings when new and could easily go 400,000 miles unless something happened to them and everyone I've seen that has rebuilt never lasted. They were built for economy more than power and if used for the purpose designed would last a long time. If GM had engineered things a little differently there would be a lot more still running today. The 6.5s I've owned have pulled every bit as good as a 454 but you have to be careful when towing. Again this is just my opinion!
 
cac (charge air cooler) aka inter cooler or inner cooler
Basically think: radiator. But instead of antifreeze inside it is the air after turbo. And yes they help a lot.

A fairly common and affordable set up is getting a factory dodge one from a junkyard- I forget the year but there are multiple threads here about guys doing it. I have one of the dodge ones sitting in my garage for over a decade now from when ine fell in my lap, but wont fit my hummer without serious mod so hasn’t happened yet. Figured I might end up with another 6.5 pickup and have it go in there. Often you can get the stock ones from diesel performance shops for $10- scrap weight or free like I did because they are replacing stock with a wazoo banks $1200-1500 unit.

Yes the aftermarket ones work better if you can drop the cash for one. But for those of us not in the big money game...

Look into the build thread of n8in8or to see a great example of using water to air cooler. They work WAY better than just air to air. Basically think a radiator, small electric pump, going to a heater core sized radiator. The heater core sized one is inside a box that is in between the turbo and intake manifold. The hot turbo air passes over the coolant in that system and cools the hot air even faster. Twisted Steel Performance just opened up to the market the most awesome intake manifold with wac (water air charger) inside it. With the better flowing intake design and the cooler it is amazing! Pricey, but not where you want to pinch pennies because a failed wac can hydrolocyour engine.

But you have a legit issue to solve- definitely need to square that away first.

@Grisley1958
I ran the shop for probably the largest fleet of 6.5s outside the military, at an oil/fuel company. We did a lot of testing for different mfrs including gm and the 6.5.

The biggest problem with rebuilds is the block is damaged by time people get into it,
The real max operation temp being 220 is time to pull over or damage occurs, and something on this we learned that the gm engineers freaked out on when we showed them- the harmonic balancer failure rate. We learned replacing them at 100,000 mile intervals was the answer. a 454 can run it 250k miles then rebuild and possibly re use. A horrible mistake on a 6.5. Never get the cheap brands- many here will confirm failure in 30k miles occurs. Because of the compression we have and how ridiculously out of balance the tolerance is for these engines- a shifted balancer will snap a crankshaft in no time. This is IN MY OPINION- not proven- the cause of the cracked and broken main webs. Every lost crankshaft/ main web we found bad balancer. We inspected each truck as they came in and noted mileage, started replacing them in a couple different intervals and found 100k to be the time. Never lost a block or crankshaft that had that done after that, except the aftermarket ones we tried that obviously failed early- complete outer ring separation by 50-60k miles. We did not have fluidampr balancers back then. If you can afford them- thats the best answer- they simply wont wear, so will outlast new engines and can be reused on the replacement/ rebui

In that fleet we had so many trucks that could hit 100,000 miles a year. Literally drivers swapped shift and didn’t shut off the engine. 3 man team on service while the driver say in the truck over the pit. Same thing on the gasser pickups with gmt400 trucks we had.

And yes the select fit bearing thing gm did - many people just buy a set of bearings and don’t realize the color coding thing. Slap them in and wile out bearings/crank in no time.
A 6.5 is a particular engine to rebuild and that why so many failures occur.

A 6.5 is NOT the engine to learn how to rebuild on.
But done properly, and making certain improvements that gm nor gep ever did- you can get a longer life out of a 6.5 than factory. But it will cost.
 
I agree with your post 100%!
The harmonic balancer is one of the first things I check when I get one. Love the fluid dampers but they are pricey! Put one on my 96 when I fixed a antifreeze leak up front and switched it over to mechanical injection ( it is standard NV4500) and whether it was the new pump or damper or a combination of the two, but now it has almost no vibration. Probably has 100,00 miles since that work and still going strong!
 
@Grisley1958 please let us know if the GMT800 (you said you have one from a 2001) lower control arm will indeed direct fit with the GMT400 platform. Lower control arms for 88-98 are only available from junkyards at this point and I've never come across real world confirmation of the newer lower control arms being interchangeable. I have a LCA that is so worn ball joints need to be welded in every time they're replaced so I'm very interested in knowing if there's a solution to my problem that can use new parts!
 
I will let you guys know about the lower control arms. I've read that they will fit but won't believe it 100% until I see it myself. For the $100 I spent on the parts I got, it was well worth it to me to gamble that it will work. Holding it up under the stamped welded one that's on there now, it looks like it will work but, I'll know soon. This isn't a priority right now as I have plenty of trucks to drive, I want to take my time and enjoy the project.
 
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