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Old 03-01-2017, 02:46 PM   #1
stephen p
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long distance towing questions with 1978 c30 3+3 dually

I posted this thread, and came to the conclusion that it was a bad idea with a half ton... http://67-72chevytrucks.com/vboard/s...86#post7866586


So I've run up on a 77 or 78 c30 camper special 3+3 dually 454, th400.. i can get it cheap, motor is seemingly sound, recent rebuild, for whatever reason, it has a torker intake (low rise single plane) that i will probably switch out for an older stock dual plane. I'm assuming it probably has 781 heads. I can get it cheap. Here's where I'm at. As explained in the thread, I'm moving from jackson ms to portland or.. i have to haul my kz1000 motocycle, tool box that's 700 lbs unloaded, random misc stuff, as well as my 69 swb c10 big block truck, on a u-haul trailer.. I've got a 2004 ram 1500 hemi quad cab, but there's no way i trust the dodge to go 2500 miles with that kind of load, especially being a high mile truck. I can also fix the old chevy on the side of the road, even if that means a Craigslist engine or trans. Provided the c30 is mechanically sound, would it be up for that kind of load and distance? It should be a 3.73 truck. Would 70 mph be out of the question? Im guessing in can expect around 8mpg? Shipp9ng my stuff is out of the question, and I'm getting the truck cheap enough, I'm pretty sure i could quick sell the truck and profit once I'm there.
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Old 03-01-2017, 07:48 PM   #2
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Re: long distance towing questions with 1978 c30 3+3 dually

If everything is in good shape on the truck it'll tow 5 tons as far as you care to take it. Not at a sustained 70 MPH, but 55-60 won't be flogging it. However, if it's not mechanically sound, getting itself down the road could be a challenge. The truck is rated for substantially more than the load you describe, but condition is everything - weight of the bike and toolbox both in the back of the truck isn't out of the question. The 454/TH400 is the best combo (at least as far as automatics go) they put in these trucks and 3.73's are a good gear for long hauls. 8 is a good, conservative number - I wouldn't expect any better than 10 from one in good, but used, condition.
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Old 03-02-2017, 11:07 AM   #3
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Re: long distance towing questions with 1978 c30 3+3 dually

I have a 82 ,K-10 I bought new.
I put a 454/T-400 in it and it has 373 rears.
I've pulled my 28" travel trailer all over the country with it.
With my Honda 3-wheeler in the bed,along with a lot of tools in my gang box with a camper shell on the bed.
It also has 33x12.5x 15 tires on it.
Worst that ever happened was I burned out the trans in Hays,Kansas and had to replace the plastic governor gear a few times.
Usually got around 8 miles to the gallon.
I think you can do it with a one ton truck.
Gonna have to dump the Dodge though!
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Old 03-02-2017, 03:34 PM   #4
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Re: long distance towing questions with 1978 c30 3+3 dually

Like others have said, if everything is in good shape, that's an easy load for that truck. Years ago, I worked with a guy that had a 75 Chevy 3/4 ton with a 1 ton rear end, 454 mated to a 4 speed manual. Used it to haul his 5th wheel travel trailer all over the country. Often passed cars struggling up the mountain grades.

I wouldn't change the manifold since it might be there due to a non standard cam installed during the rebuild. Just use it and sell it once there. The less you spend the more you can profit. If you decide to keep it, then you can start changing things.
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Old 03-06-2017, 01:11 PM   #5
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Re: long distance towing questions with 1978 c30 3+3 dually

As long as everything is sound you should be good, I moved from Houston Texas to dayton ohio with my 83 c30 and had zero problems, except for one tank working, so 8 had to stop for fuel every 120 miles
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Old 03-06-2017, 01:40 PM   #6
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Re: long distance towing questions with 1978 c30 3+3 dually

Whether or not 70mph is reasonable really depends on tire size... but it probably isn't. My C20 is 350/350/4.10/30.5" but I very rarely go that fast. If you do go that fast, 8mpg seems optimistic.
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Old 03-06-2017, 02:16 PM   #7
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Re: long distance towing questions with 1978 c30 3+3 dually

The thing I would be most worried about is the brakes. People get all excited about what the truck can haul, but if you can't bring that load to a stop, especially in an emergency or on steep declines, all the towing capacity in the world won't do you any good at that point.

My advice would be to find a later model, early-mid 2000's 2500HD or 3500HD. They have newer, more reliable, engines, better transmissions, Overdrive, all the extra coolers built in, hydroboost brakes, and 4 wheel discs. Not to mention better mileage (I average 11 mpg with my 6.0L when towing, with an 18' steel trailer, bed full of tools/equipment, and a full size truck on the trailer), and a more comfortable vehicle overall for a long haul, especially with A/C!
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Old 03-06-2017, 02:22 PM   #8
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Re: long distance towing questions with 1978 c30 3+3 dually

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Originally Posted by Nick_R_23 View Post
The thing I would be most worried about is the brakes. People get all excited about what the truck can haul, but if you can't bring that load to a stop, especially in an emergency or on steep declines, all the towing capacity in the world won't do you any good at that point.

My advice would be to find a later model, early-mid 2000's 2500HD or 3500HD. They have newer, more reliable, engines, better transmissions, Overdrive, all the extra coolers built in, hydroboost brakes, and 4 wheel discs. Not to mention better mileage (I average 11 mpg with my 6.0L when towing, with an 18' steel trailer, bed full of tools/equipment, and a full size truck on the trailer), and a more comfortable vehicle overall for a long haul, especially with A/C!
C30 disc/drum brakes are adequate for these needs. Newer technology is nice, but the old stuff is still capable of getting it done.
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Old 03-06-2017, 07:03 PM   #9
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Re: long distance towing questions with 1978 c30 3+3 dually

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Originally Posted by Nick_R_23 View Post
The thing I would be most worried about is the brakes. People get all excited about what the truck can haul, but if you can't bring that load to a stop, especially in an emergency or on steep declines, all the towing capacity in the world won't do you any good at that point.

My advice would be to find a later model, early-mid 2000's 2500HD or 3500HD. They have newer, more reliable, engines, better transmissions, Overdrive, all the extra coolers built in, hydroboost brakes, and 4 wheel discs. Not to mention better mileage (I average 11 mpg with my 6.0L when towing, with an 18' steel trailer, bed full of tools/equipment, and a full size truck on the trailer), and a more comfortable vehicle overall for a long haul, especially with A/C!
I didn't realize a 2500HD with 6.0 got Hydroboost, interesting.

Even so, the heavier duty square body brakes are good. My recollection is that my C20 has bigger rotors than a 2500HD of the era you speak of (not by much, but a little). Obviously no ABS though.
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Old 03-07-2017, 08:42 AM   #10
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Re: long distance towing questions with 1978 c30 3+3 dually

There is no replacement for displacement so 454 engine wins big time over the 6.0 in the newer 2500 HD's.
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Old 03-07-2017, 09:18 AM   #11
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Re: long distance towing questions with 1978 c30 3+3 dually

Carbureted 454's suck an unbelievable amount of fuel, without an overdrive, and 70 MPH. OMG! Maybe 4 MPG.

IMO , not sure how long that motor will last cruising it at 3000+ RPM.
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Old 03-07-2017, 10:43 AM   #12
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Re: long distance towing questions with 1978 c30 3+3 dually

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Carbureted 454's suck an unbelievable amount of fuel, without an overdrive, and 70 MPH. OMG! Maybe 4 MPG.

IMO , not sure how long that motor will last cruising it at 3000+ RPM.
so do f.i. 454's!
my fuelie 454 crew can manage 'bout 5-6 mpg's empty, 3 or 4 when towing with the camper....but it does run all day long at 3200 at about 55-ish.... (4:56's)
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Old 03-07-2017, 12:07 PM   #13
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Re: long distance towing questions with 1978 c30 3+3 dually

I'm about to be in the same boat.. kinda.. bought a c30 454/400 to tow my boat.. trying to decide to take it on the long trips this summer.. first trip is 11 hours and 650 miles each way towing 7k boat.. month of June will have 2500 towing miles

3:73 gear truck, thinking if I can get some 285 tires under it I'll do that to help with rpms.. if I could run 65 comfortably all day I'd be happy.. just used to running 80 with the dmax lol.
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Old 03-07-2017, 12:15 PM   #14
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Re: long distance towing questions with 1978 c30 3+3 dually

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C30 disc/drum brakes are adequate for these needs. Newer technology is nice, but the old stuff is still capable of getting it done.
They aren't terrible, but remember that the OP is looking at a "cheap" truck that is nearly 40 years old...when were they last serviced? What condition are they in now? I'd rather not find out during an emergency stop.

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I didn't realize a 2500HD with 6.0 got Hydroboost, interesting.

Even so, the heavier duty square body brakes are good. My recollection is that my C20 has bigger rotors than a 2500HD of the era you speak of (not by much, but a little). Obviously no ABS though.
Yes, even the early 1500HDs got hydroboost. It was a very nice setup.

Quote:
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There is no replacement for displacement so 454 engine wins big time over the 6.0 in the newer 2500 HD's.
This is some pretty old school thinking...today it's more about engine efficientcy than it is about simply cubic inches. I've towed with both and I can tell you that I was less than impressed with the 454, new tech is where it's at. That '78 454 was rated somewhere about 240hp/370lb•ft, when it was new. Even the older 6.0L was rated at 300hp/360lb•ft, at nearly a 100 cubic inch disadvantage. Some of the later ones got bumped to 361hp/385lb•ft! The 454 does have a longer stroke, but that's about the only advantage you'll find with that engine. The 6.0L is lighter, more efficient (better mileage/more hp per cubic inch), won't overheat on long climbs, fuel injected, backed by overdrive, and will outlast a 454 by a long shot. To me, guys that are stuck on 454s are there for the badge. Modern tech has left these engines in the past. Sure, they can make reasonably cheap power, but when there are many better options out there today, take advantage of the technology available!
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Old 03-07-2017, 03:20 PM   #15
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Re: long distance towing questions with 1978 c30 3+3 dually

The 454 makes more torque at lower rpm, while the 6.0 makes the torque at higher rpm. I've certainly seen people claim that, comparing a 454 truck to the 6.0, the 454 tows better. Don't know if it's true.
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Old 03-07-2017, 04:17 PM   #16
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Re: long distance towing questions with 1978 c30 3+3 dually

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Carbureted 454's suck an unbelievable amount of fuel, without an overdrive, and 70 MPH. OMG! Maybe 4 MPG.

IMO , not sure how long that motor will last cruising it at 3000+ RPM.
They are thirsty but the very worst mine's ever gotten was 9.5, towing a 9,000 lb. trailer 450 miles at 60-65. And they will last.
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Old 03-07-2017, 04:24 PM   #17
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Re: long distance towing questions with 1978 c30 3+3 dually

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Whether or not 70mph is reasonable really depends on tire size... but it probably isn't. My C20 is 350/350/4.10/30.5" but I very rarely go that fast. If you do go that fast, 8mpg seems optimistic.
4.10's with 30.5" tires is on the short side. My '85 with 32 inchers and 4.10 is right in the sweet spot at 60, doesn't protest at 65, but you can tell everything's spinning good and fast at 70+. 3.73's put a truck with 32" tires at 2,800 @ 70, which if you look at factory literature for the mid 80's truck 454, is right at its torque peak.
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Old 03-07-2017, 04:57 PM   #18
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Re: long distance towing questions with 1978 c30 3+3 dually

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4.10's with 30.5" tires is on the short side. My '85 with 32 inchers and 4.10 is right in the sweet spot at 60, doesn't protest at 65, but you can tell everything's spinning good and fast at 70+. 3.73's put a truck with 32" tires at 2,800 @ 70, which if you look at factory literature for the mid 80's truck 454, is right at its torque peak.
Hmm good to know
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Old 03-07-2017, 08:08 PM   #19
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Re: long distance towing questions with 1978 c30 3+3 dually

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4.10's with 30.5" tires is on the short side. My '85 with 32 inchers and 4.10 is right in the sweet spot at 60, doesn't protest at 65, but you can tell everything's spinning good and fast at 70+. 3.73's put a truck with 32" tires at 2,800 @ 70, which if you look at factory literature for the mid 80's truck 454, is right at its torque peak.
That's right!
I ran mine with 33's all over the country(including Canada!)
It did very well on the interstate,but was pretty sluggish in the mountains.
The 454's low end torque(and,low gear) was the only thing that saved me on the hills.
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Old 03-08-2017, 08:31 AM   #20
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Re: long distance towing questions with 1978 c30 3+3 dually

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so do f.i. 454's!
my fuelie 454 crew can manage 'bout 5-6 mpg's empty, 3 or 4 when towing with the camper....but it does run all day long at 3200 at about 55-ish.... (4:56's)
Doesn't sound right , My combo gets 10-12 pulling all this.

Quote:
Originally Posted by slotard View Post
The 454 makes more torque at lower rpm, while the 6.0 makes the torque at higher rpm. I've certainly seen people claim that, comparing a 454 truck to the 6.0, the 454 tows better. Don't know if it's true.
Iv'e had both , I prefer the 454

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Originally Posted by Alex V. View Post
They are thirsty but the very worst mine's ever gotten was 9.5, towing a 9,000 lb. trailer 450 miles at 60-65. And they will last.
I agree

Quote:
Originally Posted by Nick_R_23 View Post
They aren't terrible, but remember that the OP is looking at a "cheap" truck that is nearly 40 years old...when were they last serviced? What condition are they in now? I'd rather not find out during an emergency stop.



Yes, even the early 1500HDs got hydroboost. It was a very nice setup.



This is some pretty old school thinking...today it's more about engine efficientcy than it is about simply cubic inches. I've towed with both and I can tell you that I was less than impressed with the 454, new tech is where it's at. That '78 454 was rated somewhere about 240hp/370lb•ft, when it was new. Even the older 6.0L was rated at 300hp/360lb•ft, at nearly a 100 cubic inch disadvantage. Some of the later ones got bumped to 361hp/385lb•ft! The 454 does have a longer stroke, but that's about the only advantage you'll find with that engine. The 6.0L is lighter, more efficient (better mileage/more hp per cubic inch), won't overheat on long climbs, fuel injected, backed by overdrive, and will outlast a 454 by a long shot. To me, guys that are stuck on 454s are there for the badge. Modern tech has left these engines in the past. Sure, they can make reasonably cheap power, but when there are many better options out there today, take advantage of the technology available!
Yes the LS is better, butt I guess my gen V 1991 fI injected is way better then the 70's versions. Plus I like the 1991 grille.

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Old 03-08-2017, 10:17 AM   #21
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Re: long distance towing questions with 1978 c30 3+3 dually

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Doesn't sound right , My combo gets 10-12 pulling all this.
Iv'e had both , I prefer the 454
not too much stock-ness left on my crew Deserter...
edelbrock cam and fuel injection, T400 with 4:56's = glug, glug, glug...
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Old 03-08-2017, 11:54 AM   #22
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Re: long distance towing questions with 1978 c30 3+3 dually

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so do f.i. 454's!
my fuelie 454 crew can manage 'bout 5-6 mpg's empty, 3 or 4 when towing with the camper....but it does run all day long at 3200 at about 55-ish.... (4:56's)
What the ?? My CC Dually gets 10-11 empty and I can pull 9 towing if I keep it 60-65.
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Old 03-08-2017, 12:25 PM   #23
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Re: long distance towing questions with 1978 c30 3+3 dually

OE 454 that's .030 over w/flat tops
rebuilt stock 'peanut-port' heads
RV/towing grind cam
Edelbrock TBI intake + spec'd ECU chip
th400 w/shift kit
1 3/4" full length headers, true duals w/H pipe
heated o2 sensor
mechanical fan w/HD clutch
4.10's & 31.5" rear tires (235/85-16's)

9mpg on a good day @ ~3k rpm/65mph.
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Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive.
It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.....

Cubic inches is like Indiana Jones with a cheap pistol.
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Old 03-08-2017, 12:27 PM   #24
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Re: long distance towing questions with 1978 c30 3+3 dually

It seems like the 454 keeps getting knocked. The 6.0 is a very good engine, no doubt about it! But the 454 has been around for a long time and mine has happily accepted anything I could throw at it and keep coming back for more! I've towed plenty up the Altamont Pass, at 65, with plenty more on reserve if I wanted. My truck has 4.56's, 35 inch tires, and a 465. Mileage was about 8mpg towing. My buddy sold his 02 2500 with a 6.0 because he hated the 10 or so mpg around town empty.

As long as the truck the OP is looking at is mechanically sound, and brakes are good, he should go for it!
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Old 03-08-2017, 01:00 PM   #25
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Re: long distance towing questions with 1978 c30 3+3 dually

Sounds like my 10mpg expectation wasn't unrealistic.

Time for a tune up and the long tubes to get installed.
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