hey im wanting to do a frame off build up on my 73 f350 crew cab, its been converted to a 4x4 and has a dana 60 front. now my idea for it is to go with a caterpillar c7 acert with the allison and change it to a dually, i wanna go with cat becouse over the years ive become to love their reliability and im tired of seeing fummins and wanna do something a little more custom. i found a place that does c7 acert performance, and could easly get way more hp and torque than i need. im trying to aim around the 800 hp and 1200 ftlbs reliable. now my biggest concern is how im going to get the front end to support 1700 lbs, how im gunna keep it cool, and how im gunna keep from breaking axles! i would love some input on this!

 

 

Great Looking truck. From the picture, it kind of looks like a big hub dana 44. The low pinion variety like this.





But I have been wrong many times before.

While I admire your creativity. I think the caterpillar motor is a tad ridiculous. It's not that it couldn't be done, but unless you have serious skills, time, AND money, This will not be very cost effective, and it will be very, very hard to get right.

Every single component of the truck will have to be addressed, and you'll will have to apply massive amounts of insulation to combat the crazy vibrations from this motor.

I have one similar to this in a bob truck, and even the truck which is built to handle this type of engine, vibrates like crazy, not to mention the abysmal mileage, and expensive maintanence procedures. Parts for cats are not cheap as I am sure you are well aware, and this will get complicated quick, and will be even more complicated when something fails.

Now to me a 460 would be much reasonable. For a fraction of the cost you can have a motor that will bolt right in, and can be made into a very, very fun powerful vehicle, that's what is in my crew.

That being said, go for the cat swap. It will be very different, and very impressive when you get it done. Maybe you could make it have a similar stance to an f550, heck, some of that drivetrain might lend itself to your project.

 

My advice would be change from cat to international. Get a DT360 they are roughly the same size as a cummins but comes from the DT bloodline. But if you want the kitty here is what I would do. Axle wise, find some Duce and a half rockwells. Frame: fully box or have a replacement made from heavy wall rectangle tubing. I don't think the weight will be the biggest issue, I'm leaning more that the torque of the cat will twist the weak parts of the frame and driveline. Just my thoughts. I saw on the local Craigslist about 2years ago a guy had stuffed a DT 466 in a crew and set it on Rockwells, slick truck, but I didn't have the 6 or 8 grand he wanted for it. Ok back to your idea, if your up to it go for it and have fun getting to your goal.

 

Closed knuckle Dana 60's had the same hubs I think.

I also think everything from the knuckle out is the same as a HD Dana 44.

 

What will be your primary objective with the completed truck? Just for show, towing, off-road etc?

Did you do the 4x4 conversion? If so, what did you use as donors for the conversion? I have a 75 F350 crew cab that I may want to convert to 4x4. I know there a quite a few threads here on 4x4 conversions, I'm just curious as to how you may have accomplished it.

Not quite twins but pretty close

 

I meant not quite identical but close enough to pass as twins.

 

Ridiculous, maybe, but impossible? NO. I don't see any need to fabricate a new frame for the truck, it will handle the power output with no problem, although some boxing might help. You should see the abuse that the truck pullers put their trucks through...

Axles: If you do indeed have a low pinion 44 or 60 in the front, I would recommend going with a high pinion king pin D60 because it will be much better at handling the weight. Rear should be at least a 10.25 Ford axle, a Dana 80 would be better (probably your best choice if you are going to a dually). The 80s will handle an incredible amount of abuse, some pullers I know are pushing 1300-1400 hp through them with 12v Cummins motors.

Cooling: A large aftermarket rad will be best. Depending on what it is used for, cooling shouldn't be much of an issue. If you are planning to tow 18,000lbs up a mountain then it would be an issue, but for a street toy the engine will never see sustained loads for long enough time to cause cooling problems.

Physical dimensions will likely be an issue. A 440ci inline six diesel is a big motor. I would guess that the dimensions would be similar to a DT466 IH motor, which I have seen shoehorned into pickup chassis. The 466s require heavy firewall/trans tunnel mods, and don't leave much room for a radiator. Here is a link to C7 specs: http://www.cat.com/cda/files/2200276..._20HR_20P1.pdf

 

I want to know how you plan to get 800/1200 out of a C7. Those are big numbers for a 7.2L engine, especially the 800 part. There just isn't that much aftermarket support for them and the ECM probably won't allow it. Don't get me wrong, I'm a hardcore CAT guy. I own a couple 3406E's and have put hundreds of thousands of trouble free heavy haul miles on them, but between the expense, the lesser availability of parts, etc, I went with the Cummins in my Highboy. Not only that but unfortunately the reliability factor started to decline when CAT introduced "ACERT Technology" in 2004. It's not their fault. Environmental agencies have been trying to legislate emissions technology into existence faster than it could be developed which led to the big diesel manufacturers rolling out crappy engines. That's why CAT got out of the highway engine buisness a couple years ago and why I won't own one later than '03. If you're determined to run a CAT go with an erlier 3116 or 3126. The electronics are simpler and they're less problematic.

 

I have the tendency to over-engineer things a lot so if I have the abillity to do so I will. On the other side of things if something breaks you have now found the weak spot. And if you look at most NTPA 4x4 pulling trucks they use a custom built tube chassis. At least the ones I've been hanging around lately.

 

Yes, most of the open class pullers use custom chassis, but they are up around the 1500-1800hp range. Tube chassis are not allowed in the "street" classes we run in. We've put 800-900hp through stock Dodge frames with no issues, and our engine builder is in the 1300-1400hp range with his Cummins on a stock frame. It is amazing what some of these trucks can handle...

 

To answer some questions, i was wrong it is a low pinion dana 44 front end. I have been told many times to go with the dt466 but im pretty sure i can get alot more power out of the c7. and their are some performance parts for the c7 out their, one of my favorites is Performance Diesel Inc that with a lil thinking and im hoping i can get some bigger numbers out of it. i thought about going with a 3126 cat cuz i can pick one up for really cheap but i dont know if i can get those kinda numbers out of it, what im thinking im going to have to do is box in the frame a lil, maybe go with some rockwell 2 1/2 ton axles, i dont want this thing to high up cuz im mostly going to be towing a Very large flatbed goose neck thats why i want the dually. i think the hight its at is perfect, gives me great clearance for when i get in some ****ty fields or rough roads but its not to high that i dont look like a ******* with a trailer on, i found a good place online for rockwell axles its Red Barn Customs, 2.5 Ton Rockwell Axles, Mud Boggers, CNC Plasma Cut, Yale Mich im likeing the fact of lock out hubs cuz their will be some high way miles out on it. the truck in the summer time will be used to pull 3 mud boggers to mud races all over the north west, in the fall it will be used for harvest, and pulling trailers for hunting, winter probably park it unless theirs a need for it. i want to be able to pull anything i put on a 42 foot trailer up any kinda hill and freeway at 80 with ease, and be able to get 1 ton hay bales on a 42 foot trailer out of ****ty fields with ease and with out breaking ****. and maddogjohnson i didnt build it i bought it that way, i got lucky and picked it up for 2k the way the pic was taken, i can send you pics of the front end on how it was done, they used a 78 79 stearing box mounted on the side of the frame ill have to take some pics so you can see it works great!

 

I'd love to see some pics. Post em up here if you think others will want to see them, otherwise my email is maddogjohnson@hotmail.com

 

With what your wanting to do on the highway I don't think rockwells will be up to the challenge. I would have to agree with ford141 on this one and go with a kingpin D60 up front and sterling 10.25 or D80 in the rear. Gear wise maybe try 3.73's so you can have the 80 mph speed and not rev the cat to the moon to get there. Also for ride height have you looked into air bags? If the cat has the compressor still on it you will just need the tank and lines. You could have the best of both worlds (lifted when needed and leveled for towing) and even be able to fine tune the stability of whatever load you would be hauling, not to mention an on board air system on a tow rig, to be able to fix anything at the mud drags, the possiblitys are endless.

 

how about a 3208? Those are pretty nice engines!!! On a more serious note, I think the 800 hp c7 is a pretty tall order as well. I might look to the earlier models as well or I personally would go with a 5.9 or a 3.9 but i appreciate your thinking out of the box with the cat thing. That is a lot of weight, a big oil pan to clear a front axle, and a big radiator to cool 800 ponies. I might look for a front 60 at least or even go to the newer f superduty and fab in a dana 70 front. To elaborate more, An ALison? Come on man!! Allison is a division of Gm, Might as well a turbo hydramatic 400!!! Scab in a 6.5 turbo and head to the tractor pulls!!! I would look into a NV 4500 or NV 5600 or a rockwell trans, they hold good. If you actually see 800 HP, you might need an auto, but I think a 5,6,or7 spd would support a C7 and those can't be traced back to GM. Just my opinion.