Got some bad news on my '95 1-ton. Blew a head gasket. Here is my dilema. Do I have both heads rebuilt or is it better to just install a long block. $1800 vs. $6600 for the long block. My concern is that by only repairing the heads, I'll cause future problems with the rest of the engine. The truck has the NV4500 5spd and 135,000 miles on it.

Pull the heads and inspect the cylinders for scoring, particularly #6 and #8.


Pull the pan, wipe the bottom block surfaces with a clean towel and lacquer thinner, take a coffee break, come back and check the surfaces around the three center mains webbing.


If you do not see black varicose veins in any of the machined surfaces, the block is a good one.


Diesel fuel is a light oil - valves, seats and such do not wear like in a gasoline engine.


If it's just bad head gaskets, check the head surfaces, Fel-Pro re-gasket with new bolts, add new timing chain and both sprockets, and go on.

I am with gmctd on this one. I wouldn't consider replacing the block or the heads, until you get the heads off. I was in the exact same position as you. I have a '95 Burb with about 133k miles, which blew both head gaskets in a big way. After a hecka, mega, PITA pulling both heads myself, I decided to just replace the gaskets. <?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

There was the usual cracks between the values, and around the pre-chamber, but these are commonplace, and for the most part cosmetic.
Besides the gasket failures, both my block and heads looked pretty good. There was no warping, and just the slightest bit of pitting on the drivers side. I used a small amount of JB weld to fix the pitting, which was between cylinders, where the gasket failed, and called it good. So far so good. The rig runs awesome, gas mileage is up, and it does not consume on ounce of coolant.

Myself, I'd recommend pulling the engine itself so you can work on a stand. This makes the breakdown much easier, and inspection much better. You can knock off the oil pan, check the main webs, do rear main and oil pan seals, and clean/button things up much better.





Fire ring pitting is a serious concern as well. You could "goop" it, but odds are the thought of whether it will hold or not will be there nagging in the back of your mind.





I've got reman long blocks with NEW blocks at $4450. That's a lot of change, and the choice is yours, but knowing the history of block failures and seeing repair attempts fail, I'm more inclined to start fresh with a new block, guarranteed for 2 years. Then again, you could possibly get away with just gaskets and run another 135k...

It is a strain to drop the head on right in the engine bay, just did it for the first time and I was by myself. I could have used an extra hand to lower it on the gasket.


I agree with kennedy, that if you can, pull the engine to work on it.

My 6.5 starts real hard and blows a lot of white smoke on startup. If I rev the engine after starting and/or when the engine is warm, it still blows a lot of white smoke. Someone told me this is a blown head gasket. How do I know?

Do you lose coolant and it's not hitting the ground?


Have you had the compression tested? The injectors? glowplugs?

No, I do not lose any coolant as the engine runs in normal temp range. However, I have not tested the compression, injectors, glowplugs.