Diesel VS. Gas Which would you suggest

[Jason Mills]

If there’s one thing this thread has established, it’s that there are many good options if your intentions are only to plow snow. Not the least of which is the option of putting a flat 6 where the original one use to be.

However, as I read through each post, I couldn’t help but think that you might want more than just a plow truck.

Forgive me if I am reading something into this, but it is certainly understandable if you are wavering on the intended use. To want more than a just a plow truck is feasible.



The Cummins Diesel is decidedly the John Wayne of engines.

Now how do I describe the shot of energy that I felt when reading this?

Thanks Kevin for putting to words what I was up until now not consciously aware of:

I do want more than a stock restored M-37, as I had one, loved it and was short sighted enough to sell it. Still it left a little to be desired, in terms of being able to use it as a general purpose pick up truck..

I am thinking the first incarnation will be diesel powered, with stock gearing and the main focus being towards getting it ready for next winter.. which will include some type of hard top. I guess I will call that stage one. Stage two will be looking into refinements/improvements.. but first to get to stage 1.

[Kevin Mienke]

OK, so What if one was to take the price issue out of the equation,

it is hard to do.. BUT as a friend said to me years ago: If you pay to little and
end up unhappy what got what you paid for,

when you pay too much, and get what you wanted, you may have spent more money, but in the end you get exactly what you wanted.

Would most agree that IF the price was the same, a diesel would be preferred?

If there’s one thing this thread has established, it’s that there are many good options if your intentions are only to plow snow. Not the least of which is the option of putting a flat 6 where the original one use to be.

However, as I read through each post, I couldn’t help but think that you might want more than just a plow truck.

Forgive me if I am reading something into this, but it is certainly understandable if you are wavering on the intended use. To want more than a just a plow truck is feasible.

In such a case, it would be wise to upgrade the engine at this time since your truck doesn’t currently have one. To make the engine conversion truly profitable, and the truck its most useful, you would have to upgrade more than just your engine HP. Adding a 5 speed trans, and 4.89 differentials would be in line if you want to achieve highway speed. This can be done without losing the low-end torque. But, if you are going to make this kind of change, you will also want to make sure all other systems are above par, i.e. steering and brakes. Obviously the end result is a very usable truck, both in the field and on the highway, but the money and time spent is reflective of that.

Since we are now talking about a scenario in which money is not an issue, I wouldn’t even remotely consider anything but the Cummins.

My only concern would be the noise level in the cab. It’s decidedly loud, but I believe it is something I could get over.

I had the pleasure of seeing one of Charles’ products in person at an Iowa Rally a while ago. It was a thing of beauty. Enlightening. This particular build was something a man could drive the rest of his life and need no other truck…it could plow his driveway, haul his firewood, and carry his hinder down the road at highway speed. It could stop on a dime. It could even get the groceries.

Granted, there are a number of V- 8 gassers that can accomplish all of these tasks too. But, if cost were no issue, the ever-durable Cummins is my choice.

Gas engines have been the standard around my house forever, and I am especially fond of the old flatheads that were original to these trucks, but without a budget limitation, I wouldn't cheat yourself now and have regrets later.

I bought my first diesel truck about 5 years ago; a pre-owned 2004 CTD. I marvel at the reliability and capability of it.

The Cummins Diesel is decidedly the John Wayne of engines.

[Charles Talbert]

Now Charlie, as you routinely seem to have the need to pee further than I do (as referenced from another thread...) I'll continue to let you write your full name in the snow.

As for trash talking, I'm not bashing your setup in particular, just the short commings of a diesel engine swap inregards to a gas engine. Both have thier pitfalls, the diesels just happen to be vastly more expensive, and those funds are never recouperated in payback. But as a business owner, from your perspective, I don't lament your desire to continually trump your products. That wouldn't make for good business sense now would it? But when all the facts are considered Charles, it would take a rather creative accountant to prove that a diesel swap costs less, or equal money than a gas swap for the same performance gain. I'm not blowing steam Charles, nor am I ignorant, I can make that claim with certanty. I've read alot of wind under your avatar, but very little of it has any substance that has been backed up with numbers. Its always "the people around here", or "my clients say..." that is used to back up your opinion. Some proof would go along way to enlightening the unlearned.

Do I have any experience with your setup? None, for the simple fact that you're 5000 miles away from me. Have I ever driven a diesel truck, sure, and I liked it, just not for the price. I shoot for value Charles, and nothing you produce has ever screamed value. Your entire approach seems more along the lines of spend more money to make it better. Their comes a point Chuck, when good enough is truly good enough.

Here's the oportunity to teach and preach Charles - perhaps you've heard of the upcomming Alaska highway tour in 2012. Its in my backyard (so to speak). It would be great advertising for your services if you were to partake. Please feel free to stop by with your M37 and educate me about why your 4cyl cummins is so vastly superior. I would welcome the oportunity to be enlightend, (or at the very least, amused...)

Norm, there's nothing wrong with my memory, I belive you're just slightly confusing the engine's I'm refering too; the GM 302 and 327 where two of the best performing small block engines ever built in 1960's, period. The 305's, and 307's, which I belive your aluding to, where mediocre at best, which is why the Dodge engines you loved where able to handily thump them.

I will atest however, that everything built through the 70's, 80's, and 90's were weak at best, and none of the big three manufacturers built a power plant worth writing home about...at least until Cummins came out with the QSB 3.9L right...?

Right.....

It's a QSB 4.5, they never built a QSB 3.9. As for value, that's in the eye of the beholder I guess. We are still getting orders for Cummins installations.

Yes we can build a truck based on value and most anything else anyone wants; but I will say it is much more rewarding for us to build a high end vehicle and be able to look back and see the accomplishment in the end. I can only assume the reason you have not seen any of our projects other than the higher end stuff is because you have only been able to see the vehicles we have posted on the website. Of course the vast majority of those are the higher end projects. We can't post every project we do on the site, thus you never see the run of the mill stuff. However if you read the fine print that is there, you will find that we are happy to build projects of any type starting and stopping at any point a customer desires, per customer specs; if that is a chevy V8, so be it. We did a 327 last summer in fact for a Vietnam Vet.

The bottom line with me is this; I want our projects to scream QUALITY; regardless of the type of build it is. That can be 100% original, top of the line Cummins powered, or somewhere in between. Value has its place for sure, but quality is what keeps the business coming in.

[Jason Mills]

OK, so What if one was to take the price issue out of the equation,

it is hard to do.. BUT as a friend said to me years ago: If you pay to little and
end up unhappy what got what you paid for,

when you pay too much, and get what you wanted, you may have spent more money, but in the end you get exactly what you wanted.

Would most agree that IF the price was the same, a diesel would be preferred?

[Bruce in BC]

this is why I stopped going to Rod runs

All that dumb posturing kind of took the fun out of it . Especially the know it alls who had never turned a wrench .When it comes to placing a value on a motor swap you need consistent criteria . Milage , longevity , torque , horsepower , price , fuel milage are all factors that skew the equation . Toss in RPM and things get a bit more confusing . Each posters criteria is a bit different , so no one is right .
I am running a cummins 4bt in my Carryall . I am hoping the milage is better than the 12 miles per gallon I get in my trash truck . If I do not like it I will pull the thing and toss in a fuel injected something . It will not be a hemi or a big block though . Fuel is going no place but up . It now costs me 50 to 65 bucks to go hiking on the weekend . That is just the fuel cost . I need to drop that down .
Milage and usable torque are my main criteria , followed with longevity .
Bruce

[MasterYota]

Yota, It isn't that no one can argue your point you think you are making about diesels. When every last fact is compiled and analyzed , there is MUCH to consider before you can accurately say who got the most out of the $$ spent. Either you are just blowing steam or you simply are unlearned in the diesel world; then there are some that just won't listen to the proven facts; I honestly don't know how to make that call, so I won't attempt. Any quality build you do will be more than chicken feed; I can throw most anything together and make it run; but quality and longivity in the project is completely something else. I get bored with this common trash talking; then I have a tendency to drift away from the conversation, until someone like Norm reels me back in.

It is quite obvious that you have not experienced anything even close to one of our diesel conversion trucks; until you do, you can't talk trash as you have nothing to base it on.

Many have asked why we don't usually do V8 repowers, truth is we can't give that stuff away to the majority of our customers. Not slamming anyone who chooses to use a gasser; but that is the way it has been here.

Now Charlie, as you routinely seem to have the need to pee further than I do (as referenced from another thread...) I'll continue to let you write your full name in the snow.

As for trash talking, I'm not bashing your setup in particular, just the short commings of a diesel engine swap inregards to a gas engine. Both have thier pitfalls, the diesels just happen to be vastly more expensive, and those funds are never recouperated in payback. But as a business owner, from your perspective, I don't lament your desire to continually trump your products. That wouldn't make for good business sense now would it? But when all the facts are considered Charles, it would take a rather creative accountant to prove that a diesel swap costs less, or equal money than a gas swap for the same performance gain. I'm not blowing steam Charles, nor am I ignorant, I can make that claim with certanty. I've read alot of wind under your avatar, but very little of it has any substance that has been backed up with numbers. Its always "the people around here", or "my clients say..." that is used to back up your opinion. Some proof would go along way to enlightening the unlearned.

Do I have any experience with your setup? None, for the simple fact that you're 5000 miles away from me. Have I ever driven a diesel truck, sure, and I liked it, just not for the price. I shoot for value Charles, and nothing you produce has ever screamed value. Your entire approach seems more along the lines of spend more money to make it better. Their comes a point Chuck, when good enough is truly good enough.

Here's the oportunity to teach and preach Charles - perhaps you've heard of the upcomming Alaska highway tour in 2012. Its in my backyard (so to speak). It would be great advertising for your services if you were to partake. Please feel free to stop by with your M37 and educate me about why your 4cyl cummins is so vastly superior. I would welcome the oportunity to be enlightend, (or at the very least, amused...)

Norm, there's nothing wrong with my memory, I belive you're just slightly confusing the engine's I'm refering too; the GM 302 and 327 where two of the best performing small block engines ever built in 1960's, period. The 305's, and 307's, which I belive your aluding to, where mediocre at best, which is why the Dodge engines you loved where able to handily thump them.

I will atest however, that everything built through the 70's, 80's, and 90's were weak at best, and none of the big three manufacturers built a power plant worth writing home about...at least until Cummins came out with the QSB 3.9L right...?

Right.....

[Gordon Maney]

MPG for a diesel would vary only slightly, and it would be over 20 mpg with a 4BT. As an example, my Cummins Chassis cab empty (9,000 lbs) @ 65 mph gets 16.5 mpg. At 65 mpg and pulling another 8,000 lbs, it drops to 16 mpg.

MPG with a 318 Poly (with a 100 more HP than that SBC) would be close to 20 mpg as well. The 360 I mentioned many posts back was a 16-18 mpg ride and the LA is not nearly as efficient as the Baby Hemi Poly.

SBC's get very poor fuel economy, and it drops by 25 to 30% when a load is placed upon them. Very inefficient head design. The only saving grace is that GM made so many of them, that parts are plentiful, which is good because you will always need parts... = )

The 20 mpg with the 318 poly you mention; you are meaning an M37 with 5.83 gears?

[Gordon Maney]

More of a joke than anything, to make a point about costs, however since you answered the main question (the truck is engine-less now)

A few things to consider, fuel economy does not seem to be an issue for you, but power is.
That on it's face would eliminate 6 cylinder gas motor, unless you could find the original type engine and eliminate the cost of fabricating new mounts, trans adapter/trans etc.

The best running M37 I ever rode in was powered by a 360 V-8.
Food for thought.

PS, diesels aren't just for working, they are for great economy as well.
In a few years you will see an entire new generation of small powerful diesels in every type of vehicle.

Would you explain more of what you are meaning there?

[Charles Talbert]

Yota, It isn't that no one can argue your point you think you are making about diesels. When every last fact is compiled and analyzed , there is MUCH to consider before you can accurately say who got the most out of the $$ spent. Either you are just blowing steam or you simply are unlearned in the diesel world; then there are some that just won't listen to the proven facts; I honestly don't know how to make that call, so I won't attempt. Any quality build you do will be more than chicken feed; I can throw most anything together and make it run; but quality and longivity in the project is completely something else. I get bored with this common trash talking; then I have a tendency to drift away from the conversation, until someone like Norm reels me back in.

It is quite obvious that you have not experienced anything even close to one of our diesel conversion trucks; until you do, you can't talk trash as you have nothing to base it on.

Many have asked why we don't usually do V8 repowers, truth is we can't give that stuff away to the majority of our customers. Not slamming anyone who chooses to use a gasser; but that is the way it has been here.

[MoparNorm]

Hahaha...
As for poor head design in the SBC's, I seem to recall the SBC's of the 60's, namely the 302, and 327's kicking the crap out of every dodge and Chrysler engine produced, except for the max wedge, the 426, and 440...

Short memory... = )
273's, 340's and the 318 Poly with 260 HP would grind those anemic 305's and 327's into the ground, as would the 340 Buick that was Poly inspired, it would run circles around the 327 and 350 SBC. Too bad GM only made it for a few years, it was their best design until about 2004.
360's set up properly can get close to 20 mpg. They only get poor fuel economy when Chevy guys try to tune them... = )

[maineSS]

After you remove the original engine, it's all just iron...and as far as keeping the truck original, you're better off using a repower that doesn't require hacking the frame to fit. You'll realize a better resale price if the next owner has the option to go back the original configuration, so it helps not to scrap what came out.

Economics with regard to MPG is going to play a major role in how far the average person can afford to drive, seeing that India and China aren't riding bicycles anymore. Head design is the major factor in efficiency for the IC engine, and the Chevy 350 has had more work done on it than the rest of the competitors combined. It fits without any hacking, can be built dozens of different ways to deliver various power/torque curves, and has huge aftermarket support. It won't satisfy everybody, but it will get the job done when a gas engine repower is required.

[MasterYota]

Hahaha...

At least my economical and finacial math must've been right, as nobody seems to be arguing that point...

My engine choices have already guaranteed my spot in hades, as I put a FORD engine in an M37. Although technically, I might be all right, as all the of the big three auto makers produced an "M" series vehicle. So in theory, I'm within the blood lines for an engine choice. (It might be similar to a blood line from the bayou mind you...)

As for the GM engine, it fits, it works, and its about half the cost of a 318, which is a better engine IMO than the gas guzzler 360... If I was going to do it again, I'd actually choose a Ford 5.0L, the narrower engine fits even better between the rails, and its about 100lbs lighter. They are cheap, effective, and parts are plentiful.

In regards to the transmission comment, the SM465 4spd. found in the GM truck line, is every bit as tough and long lasting as anything ever found in a Dodge, of similar vintage. The Th400 is renowned as the strongest automatic every produced, (aside from the current alison unit), and they all used the same variants of Tcases, and axles over the years.

As for poor head design in the SBC's, I seem to recall the SBC's of the 60's, namely the 302, and 327's kicking the crap out of every dodge and chrysler engine produced, except for the max wedge, the 426, and 440...(Dodger's are a loyal bunch, even when they come in second...:))

I have no issues with putting any engine under the hood, but why spend double to keep it all dodge, when you can get the same output for half? If I treated everything with that logic, my money tree would be dead...!

Finally, if you need to ask what it gets for mileage, you can't afford it...

[MoparFreak69]

the only saving grace is that gm made so many of them, that parts are plentiful, which is good because you will always need parts... = )

ding ding ding, we have a winner!!!!!

[MoparNorm]

On a good day, I can squeak 11-13mpg on the highway. That was in its previous truck, with comparable gearing and weight and a 4spd. turnign about 2400rpm@60mph. Naturally the mileage does go down a little when working it, but thats not a real issue. The mileage for any engine under load will go down when compared to no-load useage.

MPG for a diesel would vary only slightly, and it would be over 20 mpg with a 4BT. As an example, my Cummins Chassis cab empty (9,000 lbs) @ 65 mph gets 16.5 mpg. At 65 mpg and pulling another 8,000 lbs, it drops to 16 mpg.

MPG with a 318 Poly (with a 100 more HP than that SBC) would be close to 20 mpg as well. The 360 I mentioned many posts back was a 16-18 mpg ride and the LA is not nearly as efficient as the Baby Hemi Poly.

SBC's get very poor fuel economy, and it drops by 25 to 30% when a load is placed upon them. Very inefficient head design. The only saving grace is that GM made so many of them, that parts are plentiful, which is good because you will always need parts... = )

[MoparNorm]

A GM gas v8 (305/350 ect...) will fit very nicely and perform whatever tasks needed for the minimum amount of dollars - period. Use a Gm 4spd (SM465) and a common splined yoke to connect it to the NP200 tcase. The stock rad will cool it just fine.

The diesel swap is cool, but you'll never get your investment out of it. Unless you plan to drive at least 220000 miles. The average V8 gas engine gets 14 mpg, and Charles Diesel will get somewhere around 20. The mileage difference is basically 6mpg. On a 25 gallon tank, thats 150 miles difference at 25 dollars per tank more operating cost( with diesel being about 1 dollar more per gallon). At 11000 dollars just for the engine you'll need to put 440 tanks of fuel through the truck. At roughly 500 miles per tank x 440 tanks = 220000 miles. After this mileage, the diesel will start to pay for itself, but the rest of the truck will be beyond worn out, and you'll be desparately seeking somthing more comfortable to drive.

This cost breakdown is just the engine, add in the costs of a 5spd trans, and re-gearing the diffs to 4.88, and the price just goes up and up... From an economical and financial perspective, the diesel swap isn't remotely practical.

I speak from experience, having driven and owned a SB powered M37 - it was a blast, cheap and fun, and reliable. My current M37 has a 7.0L 428ci big block under the hood; with 450hp, and over 500 ftbs, I can out hustle any light duty diesel you could fathom to swap into an M37, and I've done it cheaper. You can have your cake and eat it too...

Blasphemy!