6.0 Vortec vs 6.2 Turbo Diesel

[JHG]

I am restoring my 81 K5 (44 inch tires). I installed a low milage military 6.2 and have a turbo kit from 6.5TD (might need a new turbo though) and TH 400.

Now a friend of mine is offering me a 6.0 Vortec and 4L80.

I know that the 6.0 has a lot more power but will probably get much worse mileage. Diesel is similar priced as gasoline where I live (Iceland).

This truck is used to travel sometimes for few days at the time (trails).

Wich engine would you choose and why?

 

[tRustyK5]

6.0 all day, and the main reason is reliability. The 6.2 won't get much better fuel mileage, especially turbo'd and on 44's...and to make enough power to be worth having it will be a reliability fail.

The 6.0 is also 200 lbs lighter.

Trans is a wash, both the TH400 and the 4L80e are similar in strength. With 44's OD is irrelevant.

My two cents.

 

[JHG]

6.0 all day, and the main reason is reliability. The 6.2 won't get much better fuel mileage, especially turbo'd and on 44's...and to make enough power to be worth having it will be a reliability fail.

The 6.0 is also 200 lbs lighter.

Trans is a wash, both the TH400 and the 4L80e are similar in strength. With 44's OD is irrelevant.

My two cents.

Thanks for your two cents, I am sure that the 6.0 would be much more fun but since the 6.2 I have has only 4-5000 miles on it I think it should be good for the limited use I will use it. I was hoping that mileage would be much better on the 6.2 but I might be wrong.

 

[Smokinthehippies]

I doubt you’ll see too much better mileage out of 6.2 with the turbo.

 

[Vombrown]

For low speed trails I would say 6.2 diesel. Mileage is going to be a crappy on either engine with 44's. Turbo on the 6.2 will help for certain. If it's in and running I would leave it alone and keep it tuned. Done

 

[campfire]

I am restoring my 81 K5 (44 inch tires). I installed a low milage military 6.2 and have a turbo kit from 6.5TD (might need a new turbo though) and TH 400.

Now a friend of mine is offering me a 6.0 Vortec and 4L80.

I know that the 6.0 has a lot more power but will probably get much worse mileage. Diesel is similar priced as gasoline where I live (Iceland).

This truck is used to travel sometimes for few days at the time (trails).

Wich engine would you choose and why?

I think you can be happy with either engine, depending on your purpose. How expensive is fuel in Iceland? Mileage isn't a huge deal over here, but our gas is cheap.

Pros to the 6.2:
Dependable
Easy to maintain
Fuel efficiency
No electrical issues from water crossings.
Low-end torque...kindof. That's really just a nice way of saying there's no high-end power.

Cons to the 6.2:
140HP
It's old. Gaskets leak, parts are harder to find, etc.

Pros to the 6.0:
Reliable. It may be a little more complicated to work on, but it won't often break.
In the States, parts are easier to find.
Plenty of power

Cons to the 6.0:
Keep the electronics dry.
Eats more fuel.


Personally, I chose the 6.2. Then I chose another 6.2. Then I chose another 6.2 + a turbine kit. It's a good engine. But for most folks a 6.0 is a better choice. If you already have your truck together, I'd lean toward keeping what you have. If you were starting from scratch, it would come down to whether you favor mileage or power.

If mileage is a concern, gearing is really important. You can't casually throw an O/D at your truck, it will change your cruising engine speed range. And the power band for these two engines is different. If it's geared happily for a 6.2 without O/D (let's say 1800RPM), it will be a slow dog with a 6.0 and O/D (because the overdrive will drop the cruising speed to 1250RPM). Either way, figure out your gearing and get it happy for the engine you choose. The 6.0 wants to spin faster than the 6.2.

Either engine can mate to either transmission, though a standalone controller is needed if you mate the 4L80e to the 6.2. And the torque converter will have a different stall speed.

 

[tRustyK5]

None of the 6.0 electronics are susceptible to water, no distributor and everything else is sealed. Keep the intake dry and you're good.

 

[blazinzuk]

The 6.2 will get better mileage even when being worked to death.

I went wheeling in Alaska once and the 6.2 truck there was by far the fuel mileage king.

That is the only place where a 6.2 would beat a 6.0.

I like the clatter of the 6.2 and with the turbo power is acceptable.

There is one other advantage to the 6.2, the lack of power can and does make other parts less likely to break.

 

[Airborne_Midget]

Don't forget fuel gel with the 6.2 in cold temperatures. They are a great low maintenance, dependable engine all though lower power output. Parts are actually still really common, most of the newer 6.5l engine parts are a direct swap and it was produced until about 2002-2004 in short buses and vans.

A stock 6.0 will have more torque and hp, and comparablecompa mileage after a turbo on the 6.2l. 6.0 will be lighter weight, can definitely be built for a lot more power, cheap parts, and newer improved internals as far as metallurgy and bearing materials go. Also don't forget the need for an efi fuel system.

Trans mission is a wash, like started above if you want a dead dependable no computers, simple drivetrain run the 6.2. If you have plans to change gears, tire size, etc in the future ifI go the 6.0 route.

 

[JHG]

At the moment I am considering to keep the 6.2 and perhaps try to add an Intercooler (like to keep it simple). I am also considering to buy the 6.0 Vortec and keep as a spare (if I get bored driving the 6.2).

 

[blazinzuk]

At the moment I am considering to keep the 6.2 and perhaps try to add an Intercooler (like to keep it simple). I am also considering to buy the 6.0 Vortec and keep as a spare (if I get bored driving the 6.2).

That is the best decision

 

[Russell]

Another thing to consider is the cost to install the 6.0L vs keeping the 6.2L. You'll need to modify the wiring, install a new fuel system, cooling system, exhaust, engine mounts, instrument cluster, throttle pedal, driveshaft, transfer case and other unexpected expenses of things that crop up along the way. This can costs thousands of US dollars, often more than the donor engine and drivetrain costs.

Considering those costs, the higher fuel costs and the loss of mileage, then suddenly the 6.0L is quite an expensive venture just to get more power under your right foot.

I would run the 6.2L to mechanical failure then do the LS swap later and slowly start collecting parts.

 

[6.2Blazer]

I've owned a 1990 K5 with the factory 6.2Lsince '94 and a 6.0L 2500HD since new in '03 so have put a lot of miles on both. The K5 was basically stock when I bought it and used as a daily driver for years but is now a dedicated trail rig on 1-tons and 39.5's. The 2500HD is basically stock except for slightly bigger tires and was a daily driver and periodic tow rig for most of it's life. I'm somewhat torn on which direction to go but probably recommend staying with the 6.2 mainly because it's already installed. I've found the 6.2 to be very reliable as after somewhere around 120k miles and always ran hard it still purrs like a kitten (or rattles like a tin can, depending on what you think is normal). The only thing I've had to replace on the 6.2 was the water pump and I did replace the mechanical fuel lift pump (was having some hard starting but not sure it was the problem). I did replace the starter and radiator but that was mainly due to mud and water while off-road. The 6.2 is dirt simple to work on and has very few parts on it that will fail and leave you stranded. As one example I was out of town for the weekend and noticed the amp guage reading low one night after driving for about 20 minutes at night with the lights on. The next morning I started it up and drove 50 miles home, popped the hood, and found the alternator belt was broken. You won't do that with a 6.0L. For power I find the 6.2 (mine is slightly tweaked) to be sufficient about 90% of the time on the trails and could travel down the road at 65-70 mph easily with 38" Swampers (speed is limited with the 39.5's because of tire balance and sway). I would think with a turbo it would be decent. For parts, really haven't bought a bunch for it in the last several years but never had an issue getting stuff here in the states....but again really didn't need much.

 

[muddermilitia]

Nobody has mentioned it yet. You can run the 6.2 with up to 50/50 mix of diesel fuel and filtered waste oil. Which will cut your fuel bill in half and keep that injection pump and injectors nicely lubricated. If you have a local source to get waste oil, this could really help you. Figure out a nice way to store it and transfer it easily and set up a nice system to filter it before adding it to your tank.

Make friends with a local lube shop or municipality. That way they will be more likely to keep their waste oil clean, knowing that you are going to use it instead of just dumping any old thing into their drain pans.

 

[black dawg]

Nobody has mentioned it yet. You can run the 6.2 with up to 50/50 mix of diesel fuel and filtered waste oil. Which will cut your fuel bill in half and keep that injection pump and injectors nicely lubricated. If you have a local source to get waste oil, this could really help you. Figure out a nice way to store it and transfer it easily and set up a nice system to filter it before adding it to your tank.

Make friends with a local lube shop or municipality. That way they will be more likely to keep their waste oil clean, knowing that you are going to use it instead of just dumping any old thing into their drain pans.

They do run good on this 50/50 mix, but even with the best filtering you still need to factor in injector pump/injector replacement for increased wear on these mixtures. If you can do this work yourself, then yes burning wmo will save you money.