Seems an easy answer to me. For mileage and plenty of power, Cummins hands down. Mileage and plenty of power are pretty much diametrically opposed with a gas motor until you add MPFI and computer controlled timing. Even then you'd be hard pressed to approach a Cummins' mileage. Then there's cost. You can't get near a fuel injected 408 for $2500.

 

If you want decent mileage, then go with the Cummins. No building required. That is a non intercooled model which is actually a little hotter than the intercooled in stock form. 4.88 gearing is way low for a Cummins. You could get by with 4.10s as they were offered behind Cummins rigs of that era. 

 

Ya that's what I'm leaning towards. One thing I'm worried about with the cummins is the weight. Around here in the winter I do a lot of snow wheeling and I'm afraid that the extra weight will just make me sink and get stuck. oh ya forgot to mention the tire size will either be 37s or 38s. It will mainly be a offroad only rig but it has to be driven to the offroad destinations.

 

Cummins all the way.

 

              In my area most snow wheelers run yotas because of weight. I know of one person that has tried a CTD in snow. Even with 37's the front tried to plow, Especially in powder mix.

 

apples and oranges.  ctd for mileage - gas for offroad IMO unless you're talking 4bt.  i'm running a 300hp magnum crate engine with EZEFI, 727, 241, d60's w/4.88's and 37's - more than enough torque and gear for the technical rock crawling I enjoy most in my 4520# (without driver, passengers and gear) YJ.  a full size rig will run at least 500-700# more.

really, unless you plan on doing a lot of mud bogging I don't think you would need more than a warmed over 360 or a stockish 360 with a doubler or black box.  weight kills offroad IMO (i'm sure there are those that will argue this and that's their opinion too) and a CTD adds ALOT of weight.

good luck with your project! 

 

            I'll agree with that EY8's

 

the weight isn't a problem if you have a wide enough tire.  In fact, the weight can be a tremendous benefit off road, and my RC Oxx is a prime example.  That truck goes a lot of places that might otherwise require a front locker, and does it very smoothly.  It's called a 'Cummins Locker' - and it is the direct result of tons of traction because of the weight.  If you have a decently wide tire you can take advantage of the extra weight (and really it isn't like there's a snow plow hanging off of it - it's close in and the chassis absorbes the weight nicely.  If you put a nice 12.5 wide tire under the truck...or even better a 15.5 wide tire, you'll end up with a rock star RC, with traction everywhere.  And with a Cummins you'll have direct mechanical injection, and 20 mpg.  It's absolutely awesome.

If you use a narrow tire, well in the soft stuff it's just gonna dig holes and sink.

The tires I recommend for a Cummins-powered Ramcharger that's gonna see real off roading, is the Mickey Thompson 36x15.5 Baja MTZ radial.  The truck will be absolutely unstoppable.

- Sam

 

Well it looks like a pretty even split.    The problems I see with rebuilding a 360 is the cost. The price to rebuild a 360 and buy a fuel injection system is still a lot more than what I can get a donor CTD truck for, But I would hate to be constantly sinking in the snow. Tough Decision....

 

Cummins powered with Mattracks.  If it is truly gonna be a wheeler and not driven much on the road, then the mileage argument is pretty much nullified. Then it becomes a question of what kind of offroading are you gonna be doing? Anything major in the off camber department, and the Cummins is still a viable option due to injection. Gas is an option, but you'll regret running carbs. They hate inclines. Nothing like being at a steep camber, clawing up toward the top, then your engine sputters and dies because the angle has overwhelmed the carburetor's capability. You're at the mercy of gravity then  (The reason my 85 has a tbi engine in it now).

 

...weight kills offroad IMO (i'm sure there are those that will argue this and that's their opinion too) and a CTD adds ALOT of weight.

No doubt, a big full size truck will find the bottom of any mud hole or sand trap, and the heavier it is the worse it can get 'stuck', but...when properly 'managed' (and that's the key) the extra traction gained from the extra weight up front can be and has been absolutely awesome. We call it a 'Cummins Locker', and man I gotta say the more I wheel Oxx the more I'm loving the extra weight up front. I have decently wide tires and I avoid the deep mud holes (I'd avoid deep mud holes anyway ), and I'm going wider and adding a front locker, and I'm certain I'll go anywhere I want to. A lot of folks have been very surprised at how well Oxx handles most obstacles, myself included.

And really, it isn't like the extra weight is hanging off the front like a snow plow - it is 'buried' low within the chassis. Sure it is mostly on top of the front axle, but it isn't all that much more than a bunch of accessories under the hood and a winch. And, it brings the center of gravity down for the whole truck. I'm tellin' ya, Cummins-powered trucks off-road are freakin' awesome .

...plus, there's another huge perk - a Cummins will (almost) never overheat. I say 'almost' because I've never seen it happen, at least never off road. When crawling or 4-wheeling, there is very little demand for fuel in a Cummins - you're pretty much idling the whole time or just off idle - nearly never into the fuel/boost. Because of that, a Cummins will run nice and cool all day long. The opposite is true for a gasser - they will tend to warm up when going slow. I ran the entire second half of Hells Revenge (an awesome technical trail at Moab) in 90* + weather, and my fan module melted. My engine (Cummins) had been running 180* the whole day. After the fans quit, the entire second half of the day we ran with out them, and the engine only got up to 245*...and it never once ran any different.

Plus, the fuel economy. I can go three days of wheeling at Moab in a single tank of fuel.

After wheeling three different ramchargers, each with a 6BT Cummins, I am certain I will never put any other engine in my crawlers. Presuming the engine and it's accessory components (injection pump, lift pump, water pump, etc) are in good condition and the engine is maintained, you will gain absolute, resolute power, reliability, and economy. .

I am not saying "don't put a stroker in your rig 'cause it will suck" - not at all. My best friend Homer built a sweet 408 for his Ramcharger "Levi" and we're nearly ready to fire that dude up and go play. However he included a FAST EFI injection system, ARB front locker, headers, dual exhaust, etc etc in his build in order to get to the level of reliability, power, and performance that I had become accustomed to with my Cummins trucks, and he wanted the same with his small block. We have gone to great lenghts to upgrade his cooling systems, his EFI system, his engine, and his electrical harness(es) to get to what we feel is a very solid small block chassis, that should never stall, never quit, never overheat, and have lots n lots of torque.

Essentially, it takes a lot of upgrades to get any small or big block to have the reliability and economy as a Cummins, and truth be told no small or big block will match a Cummins for economy - just two very different animals with two very different designs and intended purposes.

Keep in mind, a Cummins was designed for towing LOTS of weight all day long - not really for 'off roading'. However, the benefits that come from a thoroughbred diesel like a Cummins can be of real benefit when used for things that require a lot less demand, ie. off roading.

You put a front/rear locker and some decently wide tires under a Cummins and there won't be too many places you can't get to.

- Sam

 

for a proven powerplant that can hit 20mpg and will see some mild/moderate trail use - CTD all the way.

but if you do the kind of wheeling that scratches paint, breaks off mirrors and busts taillights once in awhile - you'll hate that weight IMO. 

 

Cummins powered with Mattracks. If it is truly gonna be a wheeler and not driven much on the road, then the mileage argument is pretty much nullified. Then it becomes a question of what kind of offroading are you gonna be doing? Anything major in the off camber department, and the Cummins is still a viable option due to injection. Gas is an option, but you'll regret running carbs. They hate inclines. Nothing like being at a steep camber, clawing up toward the top, then your engine sputters and dies because the angle has overwhelmed the carburetor's capability. You're at the mercy of gravity then (The reason my 85 has a tbi engine in it now).

I know exactly what you mean right now I have a carb w150 and I'm really getting tired of stalling offroad. Quick question, whats the weight difference between a CTD and a Small Block?

 

i'll say 400+ pounds

 

yup, that about it - both being fully dressed.

 

That doesn't seem that bad. I guess with the money saved buying fuel injection I could buy a front locker. I think I might go talk to some of the 4x4 groups around this area and see what they think I should do. Thanks for all the help guys and I'll start a thread as soon as I get my build going.

 

...there's another thing to consider too - a Cummins is not a quiet engine - at least not the ones that are being swapped.  The older 1st gen and 2nd gen engines are old rattlers.  To some it's pure noise, but to me...it's pure music 

 

            Did some checking with some one who's been snow wheeling for ten years. Tires for what you want to do- snow wheeling with a CTD- RC, 44 x21. Even then you will have trouble in deep powder drifts. And I think this boy knows his stuff. He's built eleven rigs just for this purpose.
            That's running tires at 1.5 to 2 psi.  Not trying to dispute anyones ideas.

 

...no worries - those numbers and tire sizes sound right to me.  Snow wheeling is a very unique animal, and huge tires are a big part of it.  That's one of the reasons I want to put 46x19.5 baja claws on my big rig, and even then I'll likely use chains to pack as much snow in as I can.  Snow doesn't stick to rubber - snow sticks to snow 

 

Cummins, no brainer. Like, it's not even a discussion, the Cummins will simply outperform the 408 in every category. Especially if you start playing with it (the VE pump is limited but can still handle plenty).


For snow wheeling, there's so many factors at play you can't blanket statement "the Cummins sucks". I got on a snow trip and ended up with an S10 Blazer, a Tahoe, a Tacoma with at least a rear locker (don't recall if it was fully locked) and my 03, stock height, stock tires, mild program. And the only one that didn't get stuck? Me.

I had to have had about 25-3000 lbs on the Tahoe, and more on the yota and Blazer; I just nailed the pedal and used that weight to plow through anything. Snow up to the rockers and more in spots and she did flawlessly. Those guys woulda been screwed and calling for Search and Rescue had I not been there with my bloated pig

Dude in the Tacoma was your typical fairly experienced wheeler, and would say the same thing, that the weight of my truck and the Cummins would not be up to the task in that environment. He was shocked how well it did, as was I honestly. One tow strap between us (mine) and had I gotten stuck, I'm not sure all three would have gotten me out.

 

I think it's around 450lb different between them, and the CTD will typically have heavier axles on both ends.

Really depends on what you're gearing you're truck toward. To go fast with gas injection, 408. For economy and towing, CTD. The Ramcharger's have too short a wheelbase to take much advantage of the CTD's towing power though. And like Eric said, a 360 should cut it in terms of necessity if street performance isn't a factor.

Lots of injection out there including stock, not just one option there.

 

I'm pleased with my 408. Lots of power, silly grin on your face acceleration, and was much easier to put it my gas truck. For economy I would've preferred the Cummins. I've had both and they feel completely different. 

 

i agree with ToxicDoc on the gas strokers. i like the smooth power, easy cruising at intestate speeds and quietness. my 500 in stroked 440 will get on average 16 mpg at 70/80 mph on the interstate. that is barely touching the go pedal with plenty more if wanted. it does take some $$ to get to that point. (see specs below). i will say that considering price per gallon of 93 oct vs diesel fuel i will come out about even with a 20 gal per mile diesel truck on cost per mile. thinking about upping mpg on my truck with a 46rh/ultrabell setup. if i wanted/needed a heavy hauler work truck, it would be a cdt. ==sheriff==

 

i agree with ToxicDoc on the gas strokers. i like the smooth power, easy cruising at intestate speeds and quietness.

omg, let's not talk about the noise difference. A Cummins with a 4" exhaust and no muffler, fuel turned up, ug, so loud lol.

 

....so loud lol.

....you mean "so awesome" right??

But yes, indeed, a Cummins is a rattly, loud, noisy smelly beast...