6.2 Diesel vs SBC

[Car'n'Guitars]

Okay what are the advantages and disadvantages of each with stock set ups? Such as towing capabilities and fuel mileage?

[rcbildr]

The 6.2L will get better mileage and they have more low end torque. If you keep the oil changed and the fuel filters changed, they will go forever. Another advantage with the diesel trucks, is they come with hydroboost which gives you more stopping power. IIRC only the one ton gasoline trucks come with hydroboost.

[Car'n'Guitars]

Will the 6.2 have the torque capabilities though?

[rcbildr]

You can build them to be respectable. My diesel burb is my tow rig and I have no complaints, I love it. I can't build it up like the guys with the cummins or the duramax's build up their engines, but it was never meant to be an 800hp powerhouse.

[Car'n'Guitars]

What kind of fuel mileage do you get?

[rcbildr]

My speedo is off because I'm running 35" tires, but my guess is unloaded I'm getting around 20 and with a heavy loaded trailer...probably around 18. I think I could get a little better mileage if I change gears in the axles but I don't tow that often so in the long run I don't think it would be worth it. My Burb has 4.10 gear right now and I think it would perform a little better if I had 4.56's.

[Car'n'Guitars]

Okay so 6.2 vs a 305 which would you prefer?

[C-10 simplex]

i've done alot of thinking (bad sign right there....) about this subject:

Originally Posted by Car'n'Guitars

Will the 6.2 have the torque capabilities though?

1) The thing about the 6.2 is you can run a lower gear---like 3.73 and still get 20 or more mpg. If you do that with a gasser then the mpg goes out the window. Of course with 4sp OD transmissions, it's not really an issue anymore.



2) To me, the advantages and disadvantages of both are as follows:

Diesel has the advantage of really good mpg but may have a high(er) initial cost plus i'm unfamiliar with the setup; A new 6.5 will cost about $8000 and does not include the injectors or pump. How much do those cost?

A new 350 might cost $1500-2000. But the mpg is nowhere near as good.


So i think it boils down to how much driving you are doing. The gasser may cost .25 cents per mile in gas, while a diesel might cost .13 cents per mile.

i think in terms of total cashflow, the gas is a better move in most cases.

3) As far as which do i prefer, the 305 or 6.2, it would depend on what the intended usage would be.

[Car'n'Guitars]

I would be doing a lot of driving with it and pulling/ hauling. But I can get a 6.2 diesel for $300.

[C-10 simplex]

If towing an hauling, then i would definitely prefer the diesel over a 305.


It's good that you can get one for $300, but how long will it take to install? Realistically? Could the time be better spent earning money?

To me, it's all about cashflow, not just mpg.


For instance, my first engine swap/head gasket replacement took 3 weeks which i took off, which is about $3000 missed income. Of course, the learning experience was priceless, but strictly numbers-wise on paper it was not a good move.

[Car'n'Guitars]

Where I am and with the people I know, if I wanted to do a swap it could be done in a day or two.

[C-10 simplex]

If they can really switch it that fast, then more power to you.

But, we are talking:

1) i think you need 2 batteries? So you need another battery tray?

2) Is the exhaust exactly the same? Will it just bolt up to the small block exhaust. i've never gotten a clear answer.

3) What about brakes? i think you have to go with hydroboost. i don't even know what that is.

4) Will the torque converter be compatable and will the trans shift the same way ( i don't think diesels don't produce vacuum in the same way as a gasser?)

5) Then you need glow plugs. They need to be wired in.

6) Can we use the same gas tank, and if so what about the lines?

7) Proabably a zillion other things which i don't know about.

It is because of these reasons is why i will probably stick with gas. Plus i just like the small block.

[andrewmp6]

From what i have seen a diesel is better for towing because of its torque and you won't have a huge drop in your mileage like a gas engine will towing.The swap could be easy but does it have a trans or you going to use what you have?I wouldn't use anything less then a turbo 400 with it.Do some searching on here you might find someone that swapped one.

[Car'n'Guitars]

Yes everything would need to be converted. And if I do decide I want to do it then every aspect of it will be researched, and the truck right now has a th700r4 in it.

[joe231]

I'm a big 6.2 fan
I prefer them over a stock small block.
I have a 82 K20 Burb with a 6.2 and 700R4.
It does great in the power department.
I haven't towed anything with it yet.
You will need a diesel specific torque converter.
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[Number21]

Remember it may get better mileage, but diesel is also more expensive than gas....

I want to convert my truck to run on propane. Right now locally it's $2.79/gallon for propane, $4.05 for gas, and $4.39 for diesel.

[Corts60]

If you can pull off a cheap diesel swap, do it! I love having a diesel. It's the best of both worlds because you can have a 30+ year old truck and get the same MPG that brand new trucks are getting.

Vacuum for the tranny comes from a mechanical diaphragm pump on the engine that is in the location a distributor normally would be.

[Dsquared]

you will need to either clean the gas tank really good or get another tank. also,diesel fuel makes rubber soft so you may have to get some 2 wire hydraulic line to use as a supply line. as far as a 305, the gas mileage on them aren't that great. if you're gonna use a small block,a good stock 350 with a four barrel is better. fuel mileage on anything is determined by how far you stick your foot to it. by the way, the pumps for the 6.5s are around $1200,a 6.2 probrably ain't much cheeper and most injectors carry a core charge up to as much as $300 each or more.

[Car'n'Guitars]

Yeah I am aware of prices and all that good stuff. I guess I will do more research before I do anything. I'm not in a big hurry to do it.

[Your41Plague12]

Pretty sure these trucks had a higher tow rating with a 350/4bbl than the diesel option. The diesels were geared almost strictly for economy. They weren't really a powerhouse of any kind. I'd stick with a solid 350 and call it a day. If you want a diesel, I'd search for a diesel truck so everything is correct. If you can swing it, it would be the best of both worlds to have one of each!

[Car'n'Guitars]

Yeah only if I had more trucks...

[Edahall]

Originally Posted by Car'n'Guitars

Okay what are the advantages and disadvantages of each with stock set ups? Such as towing capabilities and fuel mileage?

350 Advantages:
-170 hp and 255 lb·ft (346 N·m) of torque
-More power at just about every RPM range
-Better pulling due to more hp and better low rpm torque
-Gasoline is less expensive than diesel

350 Disadvantages:
-About 16 mpg is about as high as you're going to get

6.2L Advantages:
Much better fuel economy. 25 mpg is easily attainable solo.
Few people want them so they're cheap on the used market

6.2L Disadvantages:
-Horsepower / Torque: 130 hp (97 kW) @ 3,600 rpm / 240 lb·ft (325 N·m) @ 2,000 rpm
-Very anemic towing engine. Doesn't have much torque and engine doesn't produce much power in the upper RPM range.
-Engine doesn't have enough power to maintain legal speeds driving solo.
-Hard on automatic transmissions due to transmission constantly hunting to maintain speed. Also, transmissions tend to overheat quickly when towing because not enough power to maintain enough speed to keep air flowing through the transmission cooler.
-Weak bottom ends (especially the newer blocks)
-Diesel fuel is more expensive


That said, I fixed the low power issue on my 6.2L so it could actually tow my 26 ft Airstream reasonably well. I installed a set of headers and free flowing exhaust. It made a huge difference and I gained some fuel economy as well. The increase in fuel economy alone has more than paid itself for the price of the headers and exhaust system. GM should have made them this way from the factory.

[Edahall]

Originally Posted by Car'n'Guitars

Where I am and with the people I know, if I wanted to do a swap it could be done in a day or two.

Have you thought about putting in a Cummins 5.9 6BT? Maybe not quite as good fuel economy solo but much more power and better reliability. There are also tons of these engines floating around due to the engine outliving the Dodge truck.

[Car'n'Guitars]

Originally Posted by Edahall

Have you thought about putting in a Cummins 5.9 6BT? Maybe not quite as good fuel economy solo but much more power and better reliability. There are also tons of these engines floating around due to the engine outliving the Dodge truck.

Oh yeah that's what I really want just can't afford it though.

[Dalaigh]

Originally Posted by Edahall

350 Advantages:
-170 hp and 255 lb·ft (346 N·m) of torque
-More power at just about every RPM range
-Better pulling due to more hp and better low rpm torque
-Gasoline is less expensive than diesel

350 Disadvantages:
-About 16 mpg is about as high as you're going to get

6.2L Advantages:
Much better fuel economy. 25 mpg is easily attainable solo.
Few people want them so they're cheap on the used market

6.2L Disadvantages:
-Horsepower / Torque: 130 hp (97 kW) @ 3,600 rpm / 240 lb·ft (325 N·m) @ 2,000 rpm
-Very anemic towing engine. Doesn't have much torque and engine doesn't produce much power in the upper RPM range.
-Engine doesn't have enough power to maintain legal speeds driving solo.
-Hard on automatic transmissions due to transmission constantly hunting to maintain speed. Also, transmissions tend to overheat quickly when towing because not enough power to maintain enough speed to keep air flowing through the transmission cooler.
-Weak bottom ends (especially the newer blocks)
-Diesel fuel is more expensive


That said, I fixed the low power issue on my 6.2L so it could actually tow my 26 ft Airstream reasonably well. I installed a set of headers and free flowing exhaust. It made a huge difference and I gained some fuel economy as well. The increase in fuel economy alone has more than paid itself for the price of the headers and exhaust system. GM should have made them this way from the factory.

Diesels an easy 6 cents cheaper then gas here, it's never gone higher then gas.