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Discussion Starter · #1 ·
So, I finally found a truck to become the victim of my Detroit swap: an M-715. Yes, you read that right. Many of us have probably thought of it, I’m doing it. Sorry if this post gets a little scatter brained, that’s just how I can be sometimes, so here we go.

I found it a couple hours away from me for a really good deal, considering I got a matching trailer, a big box full of shoes for the brakes, an entire front end (spare hood, 2 fenders w/ inner fenders attached, spare front panel, & two extra doors off of a J truck of some sort) an extra wheel & tire (making 2 spares for the truck), a set of air horns, and a few other things I’ve forgotten right now.
The truck is typical of most of AZ trucks: dirty, but very little to no rust. So far I haven’t found any on it. They didn’t paint the bottom of the flatbed before they mounted it, so it is rusting, but other than that, the chassis & body are all about as solid as I’ve ever seen, especially for anything from Kaiser/Jeep/AMC etc. I don’t know any of this truck’s military history yet, so I don’t know where it spent its life in the service, but I know the guys I bought it from were apparently doing Semi wreck recoveries with it (which I could believe. They pretty much over-built anything and everything they got their hands on), I suspect mostly in northern AZ, Parts of Cali, and possibly Southern Nevada, so its later part of life after it was retired hasn’t been easy, but nice & arid. It seems to me its spent its entire life in the southwest, there is no way it could be this clean otherwise.

Anyway, on to its current specs. The boys I bought it from converted it from military novelty with lots of potential to the burliest work truck around, basically. They jerked the military cab & fenders in favor of the stock ones off a J-2000, took out the Tornado 6 and 4-speed and planted a mildly built 292 Chevy (offy intake, 500 cfm edelbrock 4-barrel, 3 ½” or 4” air cleaner spacer that’s large enough I consider it a velocity stack, possibly a cam{still not sure}, 3 to 1 stovebolt manifolds, 3” exhaust to Magnaflow straight-through can muffler out to 4” stack) and some monster GM 4-speed I don’t even know. They were saying it was called the “five-four” for reasons I don’t remember, but basically saying it was the one they used in ultra-heavy duty applications (does that still mean it’s a SM-465? Cuz it still looks like one, regardless of their embellishment of how gnarly it is). It has no transfer case, so its just a 2wd as of the moment, but they rebuilt the Dana 70 out back and added a Detroit Locker, which works like any Detroit; great, but not so great sometimes (tight corner…. JOLT!). Font axle is inop, basically just holding onto the front wheels. And the wheels are apparently Custom made by Stockton Wheel in Stockton, Cali. They are wrapped with Military Surplus 39” Michelin XL’s, which are just awesome, for lack of better terminology. The things are huge! Which, really, the whole truck is huge, but whatever. They are big contributors in that area.

The truck also has a 4” body lift, mainly for tire clearance, which I consider an advantage, as it would have needed one anyway for the Detroit. Interior is rugged and ratty, but it works. They blacked out all but the speedo, added the dash-mounted tach, and replaced the center J-truck glove box with a bunch of guages on a hinged piece of steel. The seats are horrid, not just because they are two different ones, but they are just disgusting. I want a shower every time I sit in the thing they are so nasty. The floor is covered in an amalgamation of floor mats, rubber mat, industrial rubber flooring, house carpet, door mats, and whatever else they could find. Its truly a spectacle of awful, its amazing, loads of true red neck work truck character. The steering wheel was black & sticky w/ a worn-out oily & sticky black steering wheel cover when I got it, so I tossed the cover & cleaned the wheel as much as I considered it was worth, just to find out it was a nice brown Wagoneer steering wheel @ one point, & covered it in a spare red sports steering wheel cover I had lying around for the time being, ‘till I figure out what to do w/ the darned thing.

The bed is truly astounding. Its all 1/8” & 1/4” diamond plate & regular steel. One of my on-board air tanks is mounted on top of the little frame they built, and it has more accessory/light mounts on top of the headache rack that I really know what to do with. The headache rack has pretty much rendered rearward visibility useless, so I drive it like a box truck, or any big tractor truck for that matter, nothing but mirrors. The 4” stack’s clamps are also welded to the headache rack, which is nice, other than it needs a heat shield. I’ve burned myself a few times, and others I’ve let drive it pretty much burn themselves every time they get in & out. Also mounted to the bed are its 2 fuel tanks, the front one is about 25 gal. and the rear about 35-ish. They claimed it had about 75 gal. total, I’ve yet to see this, unless the tanks are full of crap in the bottom to the point they’re starving me 5-10 gal. ea, which I honestly don’t find that likely because they aren’t that old, but, I’m pretty certain they’re not treated; so who knows. I haven’t checked the fuel filter yet, but the in-line one in front of the carb is clean as a whistle, so maybe my poor pump is full?? Also speaking of fuel & fuel pumps, it has an external electric pump. Its not mounted on the bed, but it gives the truck a lot of character because it makes tons of noise (possibly cuz its full of ????). Although, my air compressor is mounted under the bed. I still need to run the thing because it ran off the 2[SUP]nd[/SUP] battery they didn’t throw in with the truck, so I have no idea of its state. I suspect it works, as everything on this thing so far has trouble-free for the 1200-1500 miles or so I’ve driven it (mostly cross-country, might I add. Nothing like taking off across the SW US in a truck you’ve driven 5 times and owned for a few weeks!), but its still probably the biggest unknown on the thing right now. And the bed has the two tool/storage boxes on the back, as well as the standard tow receiver & the Jaw-clamp one (funny how I’ve worked with those things my whole life & never known what they’re called. Someone please fill me in :))

What do I want out of this truck? Well, to be perfectly honest, almost everything. Everything but speed & luxury, as I know it will never be very good at either, and that’s not why I wanted it anyway. I want it to be a big, burly, manly ex-military work truck/off-roader/reliable 2[SUP]nd[/SUP] vehicle I could use as my 1[SUP]st[/SUP], that’s stone simple, easy to work on, cheap to run, low-maintenance, and unbreakable as you can build it. A simple, utilitarian & unique truck I can use as a DD of sorts. Am I asking too much? Maybe… but why not strive for perfection even though I’ll never achieve it? At least die trying, right? Maybe you’ll come up with something really good.

My plans:
Detroit 353N I have sitting on the floor, may add a turbo, may not. Probably will do bigger injectors either way.

Transmission is an issue. I can either run the NP 542/ 3-speed Spicer combo I have w/ a divorced t-case (NP205? Any other suggestions welcome J) & a huge front driveshaft & the entire bottom of the truck lined w/ gearboxes, or I’ve really been liking an Eaton/Fuller 9 or 10 speed w/ overdrive, & divorced NP205. A lot less crap to go wrong, as its only one transmission & the t-case, like a normal truck. Advice and opinion here would be awesome!!!

Either way that goes, its getting 2 ½ ton Rockwells. I’m a fan of building things right the 1[SUP]st[/SUP] time, so why not go all-out? Front axles in these are known to be total junk anyway, so if I’m going to be towing/off-roading/hauling & road-tripping w/ this thing, I don’t want crap breaking. GM 14-bolts are too expensive, D70 fronts are too rare, I’m not sure a D60 will be enough, so…. Rockwells? Biggest & best? Plus, all my wheels are already the same bolt pattern as a 2 ½ ton Rockwell, and I have massive tires. Why not?

Run on biodiesel or bio-blend (do Detroits even like the stuff? It would be nice if they did, I like the idea of running for cheap. If not, maybe I could tinker w/ a set of injectors until they do like it J)

Clean up interior, keep very utilitarian and useful. New seats, new flooring, tons of sound-deadening, tons of gauges, all thrills no frills basically. Debating A/C, May not even add a radio. Who needs one when you have a Screamin Jimmy breathing out a stack behind the cab? Besides, what 715 or Deuce & ½ has a radio in it anyway? God forbid if pimp my ride got a hold of one….. K

Add military fenders back on the front, even though the current ones just look ballsy in person.

Possibly convert back to military cab

Lots of other small or less significant things, but that’s the basis of what this truck will become as soon as I have space again, and know I’ll be settled enough that I won’t start into it and have to move or something. I’d like to go just from start to finish with it as much as possible.


Any and all advice would be awesome, and I’ll post pics as soon as I figure out why photobucket is being a screwball.

The Youngster
 

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With the direction you want to go, I would definitely get the original military sheet metal back on the front.

Might consider Unimog portals instead of the Rockwells. Same strength category, but much less weight, better ground clearance, less likely to want to occupy the same real estate as the oil pan. Probably not a 2.5-ton axle, but I'd put them at a 1.75-ton rating.
 

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sounds like a sweet project got any pics of this beast?
 

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Either way that goes, its getting 2 ½ ton Rockwells. I’m a fan of building things right the 1[SUP]st[/SUP] time, so why not go all-out? Front axles in these are known to be total junk anyway, so if I’m going to be towing/off-roading/hauling & road-tripping w/ this thing, I don’t want crap breaking. GM 14-bolts are too expensive, D70 fronts are too rare, I’m not sure a D60 will be enough, so…. Rockwells? Biggest & best? Plus, all my wheels are already the same bolt pattern as a 2 ½ ton Rockwell, and I have massive tires. Why not?
Since when are 14bolts expensive? To me it sound like you want to build this thing so big, you won't have enough engine to drive it, or not at any reasonable speed.

How about redoing the interior and doing an engine/transmission/transfer-case swap and then working on other things as you find they need it? Keep your current axles, and replace the front if you have problems with it, or find a good deal on something else.
 

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Discussion Starter · #6 ·
Like they said WE WANNA SEE PICTURES!
<br>
I’ll post pics as soon as I figure out why photobucket is being a screwball.
finally have my account sorted and uploaded some stuff, now I just need to remember how to get them to work on here! Its been a while since I've done this.

Im building a 715 with a 353 aswell
sweet deal! I always wondered if there was SOMEONE on here that had beat me too it, or at least was on the same path & I just hadn't seen it yet. you have a build thread or anything of the sorts yet?

you are gonna need some serious overdrive to keep up with those rockwells.
i have ideas for this. One part is the o/d 10 speed or the Spicer, depending on which trans rig I run. The other, I found a company that actually makes a set of 4.90's for Rockwells, right here in the good 'ol USA, so if I'm going to ask around and see if anyone has tried them and how they are. If not, I may just guinea pig them anyway (Potential bad & expensive mistake?), if I go the Rockwell route as I'd REALLY like too. My only concern with them is 1. weight and 2. the unknown of those gears, but mainly weight. they weight some 200-300 lbs. more each than what my current axles do. My poor little 353 just might not have enough poop even with a turbo.

Might consider Unimog portals instead of the Rockwells
I might. I started looking into portals in general, not necessarily Unimogs, didn't get very far. I may start my hunt again though, if it will make that big a difference in weight and still be tough as nails.  My only concern w/ portals of any type is the truck is so darned tall already, I really don't want to make it any taller as it will become a serious issue. Its already about 7 1/2 ish feet tall w/ out the stack it has on it, the stack makes it about 10 or 11 ish. Its massive! But, at the same time, it already can't fit anywhere small anyway, so.... I don't know. I'm mainly just gathering parts right now, so nothing's set in stone. I
know what I'd like to do, but it may not be feasible either.

Since when are 14bolts expensive?
Maybe I'm looking in the wrong places, or haven't looked enough, but everywhere I've looked they've been a whole lot more than I probably need to spend. Plus I have a friend putting finishing touches on a TJ w/ 14 bolts, and he spent a ton of money. As an experienced fabricator and wheeler he advised me no, unless I'm rolling in cash. I'll keep my options open, but thats what I've seen thus far.

How about redoing the interior and doing an engine/transmission/transfer-case swap and then working on other things as you find they need it? Keep your current axles, and replace the front if you have problems with it, or find a good deal on something else.
Problem is, front axle is done already. Not the knuckles and such that usually go on them, it has no carrier. They took it out when they built the truck. As I said, its currently 2wd. No t-case, front axle is only holding on the front wheels. So, when I put it back to a 4x4, it needs an axle up front. This is not an area where i can just fix it as I go along, this is an issue that will be addressed when I tear into it. Maybe its a Rockwell (or 2, as u can't just do one), as I'd like it to be, but still may not be. I've pondered just doing the front axle as they already built the back axle w/ new shafts & the detroit locker, but I'm a little concerned w/ it too, b/c I checked the fluid in it, and it came out a really ugly metallic dark green. :eek: Its days might be numbered. I'll change the fluid before I drive back to college and see what happens, but I still think looking for another rear may not be a bad idea. Hence my Rockwell idea. Do 'em both, be done. Now and for many, many, many years to come. But, as already was a concern of mine and y'all have mentioned, weight is a serious issue w/ them, and making this beast too much heavier will render my 353 woefully inadequate/useless. The Stovebolt 6 that's in it is already working pretty hard.

We'll see. I have my plans and ideas, but as y'all probably know good and well, those can get changed when doing a big project like this.

Thanks for the imput already though! I don't mean to come off as a know-it-all if I did, I've just been pondering this whole enigma for quite a while, looked at a lot of stuff as I will continue to do for a while, and am simply stating where I am w/ it as a start to this thread.
 

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Discussion Starter · #7 ·
oh, sorry myJeepisAfatty, I didn't even notice you're a new user. my bad! Welcome aboard!
 

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Maybe I'm looking in the wrong places, or haven't looked enough, but everywhere I've looked they've been a whole lot more than I probably need to spend. Plus I have a friend putting finishing touches on a TJ w/ 14 bolts, and he spent a ton of money. As an experienced fabricator and wheeler he advised me no, unless I'm rolling in cash. I'll keep my options open, but thats what I've seen thus far.
14 bolts, plural? If he's got a front 14 bolt that's a totally custom job, and I'd expect that to cost a bunch. I was thinking only for the rear. Get an older one and keep the drums or swap to disks, or get a newer one that's got disks already move your mounts and bolt it in...... add a Detroit Locker as funds allow or needs dictate. I'd only do this if the Dana 70 fives you trouble.
 

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Discussion Starter · #9 ·
14 bolts, plural? If he's got a front 14 bolt that's a totally custom job, and I'd expect that to cost a bunch. I was thinking only for the rear.
yeah, he did a front as well. He did most of the work himself, and it was still TONS of doe. That's what I'd be doing as well if I threw one up front and kept the D70 out back. Hence, not a fan, and searching other options.
 

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yeah, he did a front as well. He did most of the work himself, and it was still TONS of doe. That's what I'd be doing as well if I threw one up front and kept the D70 out back. Hence, not a fan, and searching other options.
Being expensive has nothing to do with it being a 14-bolt. It's expensive becasue he built a custom front axle from a rear axle. I am in no way suggesting you use a 14-bolt up front.
 

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If you do use rockwells you may ought to consider something with a little more oomph, maybe like a 6v-53t, I'd Imagine the Rockwells would even support a 6-71T (straight or V) Maybe even a 6v-92T, but Good bye fuel mileage, hello Raw Power!:jeep2: 400HP 1000+ft.lbs, but 2000+pounds!
 

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No build thread yet. I never remember to take pictures but I will take lots of Videos when its done.

Thanks Youngster Ive been browsing around on here for a few months I just never say anything :p

Also I dont think you will be "too" underpowered as long as you have enough gears to get it moving. An m35a2 deuce only has about 130hp and it weights 13,000lbs and they get around just fine.
 

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i think 55 is max speed with the 20 inch tires the military runs, with 53 inch i think you can get to 60
 

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Also I dont think you will be "too" underpowered as long as you have enough gears to get it moving. An m35a2 deuce only has about 130hp and it weights 13,000lbs and they get around just fine.
It'd be okay if he used a 10 spd road ranger w/ OD, but if he's going to use rockwells why not take advantage of all the strength and use a 6v-53T, or at least a 4-53T....

A 3-53n in a m715 with rockwells is like a 4banger or v6 in a 1 ton pickup, sure it'll push it if it has enough gears, but why not use a motor that won't be straining?
 

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Discussion Starter · #17 ·
Holy Crow it worked! Have some more!





Filling up w/ gas after I bought it. bye-bye $$$$......


And an interior shot:
 

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that is a sweet rig, now how about some under hood pics :D
 
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