EcoMod This!

[Gasoline Fumes]

Originally Posted by jakobnev

Maybe you can find some eco-friendly way of preheating the drive line.

That's a good idea! There are a few gallons of 80w-90 in that truck. And I know how thick that stuff gets in cold weather!

[Backtobasics]

I'm with northboundtrain.
Sell the diesel, and choose some conservative "performance" parts to make the 350 gas more efficient. Moderate camshaft, dual plane intake manifold, carb, headers, exhaust, ignition, etc will wake up the motor. Small block chevy has the benefit of being dirt cheap, so even aftermarket full billet distributors are low bucks.

Air dam or a skid plate during non-plowing times could yield a benefit. I would also look at the back, the rear bumper looks like a parachute to me, what could be done here, to help smooth airflow and decrease the wake?

A wide band setup would allow you to tune the carb better then the traditonal hot rodders... "that sounds about right" methods (I am guilt of this too). It could be leaned out during the non plow season, and richened up a bit during plowing to prevent pinging under load.

Vacuum gauge for instant throttle feedback.

[Gasoline Fumes]

Originally Posted by northboundtrain

I did this same conversion several years ago. It can still cost a lot of money, even if you already have the engine. You'll need a different flywheel, starter, exhaust, batteries, glow plug relay, etc., etc. And depending on the condition of the engine, you may need to replace/rebuild things like the injectors, injection pump ($$$), etc. IIRC, the diesel engine has oil cooler lines, so you may need a new radiator too. I remember it nickle and dimed me to the tune of several thousand dollars by the time it was all finished. Perhaps you have more parts than I did to start with, but don't underestimate the cost of all the components to get the vehicle moving.
Then you'll have to figure out how to register it, which may or may not be an issue where you live.
And finally, the old GM diesel is just not a great engine. I saw a very modest mpg increase, and the power for towing or plowing just isn't there. You probably won't ever come close to recouping the cost of the conversion in fuel savings, particularly since you don't plan to drive it a lot.
For a lot less, you could probably tune up and modify the 350 to make more power and be more efficient (headers, free-flowing exhaust, carb rebuild, engine freshen up, towing/mileage cam, etc). It would crush the 6.2 for power and torque.
Then again, the 350 may be worn out and need re-boring, full valve and guide job, etc, but if it's really worth $500, then it should still have good compression and be within wear tolerances.
Anyhow, I'm in the process of freshening up the 350 in a '77 3/4 ton and doing the above-mentioned mods, so when I saw this post, I figured I'd chime in. Hope it helps.

Thanks for the advice. I'm actually very familiar with the 6.2L and its shortcomings, it's coming out of an old rusty '83 GMC that I've had for 8 years. Plenty of power for plowing. And I've towed with it, so I know what to expect. Both engines are in good shape. I need to catch up on some maintenance on the 6.2L, but it has a recent injection pump and very good compression. I got really lucky and found the diesel flywheel, clutch and an external oil cooler with new lines in a junkyard Chevy P30 stepvan. My donor truck is an auto, so finding those parts saved me hundreds of dollars. I basically have everything to drop it in.

The 1980 is a heavy-duty 8,600 lb truck with no catalytic converters. Basically emissions exempt in NY. I can put any engine I want in it. I'd go with a 4-cyl turbodiesel if they weren't so expensive. If I wasn't going diesel, I'd put a 6-cyl gas engine in it and get the 6.2L power and mileage.

The 350 came with headers and other performance goodies. But it got around 7 MPG towing and I have to pay whatever the gas stations charge for fuel. The diesel will run on free WVO. And I like the way the 6.2L sounds.

[cleanspeed1]

Aw, c'mon man, do the car!

http://www.youtube.com/watch?v=5nfXYCKjW18

You could do a body swap on the trucks; give you a chance to clean the undercarriage up......

[Gasoline Fumes]

Caddy looks fun, but I have no need for something like that. Sounds very familiar!

Body swap wouldn't make sense in my situation. The diesel truck's frame is pretty rusty and it's a thinner 1/2 ton frame with a weaker rear axle and very rusty leaf springs. Plus I blew up the auto tranny! But it does have 3.08 gears, which would be awesome when not towing.

Nobody's going to talk me out of putting the diesel in the 1980 Chevy.

[cleanspeed1]

Alright, alright. We tried.

What have the prices for 5 speed manuals been going for?

[Gasoline Fumes]

If one turned up in the junkyard and I pulled it myself, I'd have it for about $130. But I'd need a different (and rare) transfer case, a hydraulic clutch setup and probably driveshafts as well. So probably $300-$500. And I'd only have a 30 day warranty. If I bought a 5-spd conversion "kit" from one of the transmission websites, it would cost thousands.

But it's still tempting if the parts show up. I'll be revving about 1000 RPM higher than the auto overdrive truck did at cruising speed. But that thing lugged so badly with the torque converter locked. It barely could maintain speed on flat ground. The overdrive with the 3.73 gears would be just about perfect.

[cleanspeed1]

So it sounds like a wash. Sell small block, get transmission parts, keep the 3.73s.

[northboundtrain]

Originally Posted by Gasoline Fumes

. . . Nobody's going to talk me out of putting the diesel in the 1980 Chevy.

When I did my conversion, WVO was my plan as well, and there wasn't any one who was going to talk me out of it either. I abandoned the WVO idea after realizing the engine I had wasn't worth the effort. I was a bit disappointed with the power and fuel economy (12-15 mpg with the 4-speed and 4.10 gearing), though I've heard of better mileage with overdrive and 3.73 gears. Still, I was hoping for high teens considering that most of my driving was at lower than highway speeds.

As far as your initial question--how to ecomod the truck--I'm not sure what you could do to the engine, or would want to do. It's been several years since I thought about and researched WVO, but back then it was still pretty experimental, and a lot of people were ruining injection pumps pretty quickly. Those old ID diesels will run on almost anything for a while, but eventually parts start failing if the fuel isn't really clean and the right viscosity going into the IP. I remember thinking I would definitely want to use an inline electric fuel heater right before the IP, because others' experiences were that the coolant tank heating system didn' quite heat the fuel enough. In the end, I sold the truck and went back to gas. Nevertheless if you want to modify, make the exhaust as free-flowing as possible (will BBC headers work on the 6.2?), and I remember there's a few different intake manifolds for that engine, one of which is more unrestricted than the others. Run synthetic oils all around and put in a block heater for faster warm-up times. I found my engine ran cold (I did use an external/supplementary oil cooler, I now remember) and I had a full grill block except in the warmest months of the year.

Aero mods for a plow/tow vehicle

Have fun with the project, that's the important thing, right?

[cleanspeed1]

The military spec manifolds flow the best, and the exhaust manifolds off the Hummer are almost like short tube headers. The ultimate solution though, is putting a turbo on that thing. Win,win. The thing that kills the pumps with waste oil is the filtration situation and the removal of water and acids from the stock. The Stanadyne DB pumps are pretty intolerant of contamination. The stuff needs to be heated.