Visit our Popular Forums

SafeHarbor · 06-02-2005, 12:24 PM

Hi, folks,

I wonder if anyone would comment about the suitability of this old truck for towing? It's a 1978 Silverado CC109033 long wheelbase pickup.

From the sticker on the glove box lid:

Front bench seat
Fleetside pickup box
Front stabilizer bar
V8 Engine - 454 - CID 8
Auxilliary fuel tank
Rally wheels
HD Trailer Wiring
Chrome Grille
Silverado equip.
Tinted glass and A.C.
Heavy Duty Chasis E (F44)
Speed control TR
Turbo-hydramitc TR
Red custom vinyl
L78W-15 TBLS HWY. Bias-ply

I drove it yesterday. The steering, typical of its day, is novacaine-numb and there's some body cancer that needs treating, but its been in the family and I can get it free for picking it up.

It has 94K miles on it, a small receiver, and a boat trailer hookup. The engine has been de-smoggified, has an Eidelbrook manifold, and a big evil-looking carburetor on it.

The door sticker says

Front axle 3400#
Rear axle 3750#
GAWR 6200#

I'm thinking of fixing this up to tow my '79 Excella 31'. It's the right era for my trailer, but is this truck heavy enough? With both tanks full (42 gallons, my dad thinks), is the carrying capacity going to be able to support my hitch weight? Most importantly, is this truck heavy enough to keep the tail from wagging the dog, so to speak?

My '93 Dakota (rare V8, one-ton, lwb, trailer-towing package) is right at its max towing this trailer (used it to pull the empty trailer from Michigan to Georgia), but I'm thinking that more horsepower and weight would be nice. And since I can get this Chevy free...

Thoughts anyone?

Thanks,

Lamar

wahoonc · 06-02-2005, 01:42 PM

I would go for it!...if you can afford the gas

that 454 is a beast and is what most people used to use for towing in their suburbans. Check and see what the rear end ratio is. If it is a 3:55 or better you should be good to go. I love the old pre-smog trucks

The only other thing that comes to mind is the mileage, those 454's are only good for about 100k...at least the ones I have had.

Aaron

RichardT · 06-02-2005, 02:40 PM

If your Silverado with a big block cannot tow your trailer, what can?
Not much to think about, it is suitable and capable.

SafeHarbor · 06-02-2005, 02:50 PM

Thanks, guys. I was wondering if the additional weight of the Suburbans is a big factor in choosing it over powerful pickups. How does one determine the rear end ratio? (Take the cover off and count the gears springs to mind...) Is it marked on the differential?

wahoonc · 06-02-2005, 03:00 PM

Quote:

Originally Posted by SafeHarbor

Thanks, guys. I was wondering if the additional weight of the Suburbans is a big factor in choosing it over powerful pickups. How does one determine the rear end ratio? (Take the cover off and count the gears springs to mind...) Is it marked on the differential?

There should be a tag on the rear end or possbily an axle code on a sticker in the glove compartment or possibly on the door tag. If all else fails jack it up and rotate the rear wheel one time and count the number of revolutions of the driveshaft....

Aaron

wahoonc · 06-02-2005, 03:02 PM

Quote:

Originally Posted by SafeHarbor

Thanks, guys. I was wondering if the additional weight of the Suburbans is a big factor in choosing it over powerful pickups. How does one determine the rear end ratio? (Take the cover off and count the gears springs to mind...) Is it marked on the differential?

I would think that the idea behind the Suburbans was the four doors and the covered interior space, similar to a station wagon or large sedan, but with the towing capabilities of a truck. FWIW I tow with a 1/2 ton pickup.

Aaron

SafeHarbor · 06-02-2005, 04:54 PM

Thanks, Aaron - that was what I wanted to hear - that somebody tows a 31-footer with a half-ton pickup. I did a search for product literature on this truck, and all could find was that it was called a "Big Ten" model.

Does anyone know where to look for specifications on this truck and where to decode what the installed equipment codes mean? For example, what does "Heavy Duty Chassis E" mean?

Aaron, what's the typical failure mode for these engines? I think this one needs a little work, but it doesn't smoke at startup or stumble when it warms up.

Thanks,

Lamar

PS - My Dakota gets 12 mpg towing the Excella. How much worse could this old monster be?

dinoburb · 06-02-2005, 05:23 PM

Hi Safeharbor,

I have an '82 C-20 suburban w/factory tow package that was used to tow my previous 31' Sovereign. No problem, however, it is a 3/4 ton truck with the associated brakes and necessary cooling for the transmission & engine. My only concern for your setup would be the rear ratio and the much less capable brakes. The engine and trans are the same ones in the 345 MH!

Any idea what and when work was done on the engine? The original Q'jet properly rebuilt with a new float provided 795cfm of flow, really more than a low rpm tow motor would ever use and more than enough for additional upgrades to the motor. I'm always skeptical when I see several modifications that may or may not have been necessary. Many times, unless the mods have been thought out you actually harm performance rather than improve it. Look carefully.

Since I've moved to a 34' trailer I'm rebuilding the engine with an eye to more HP ( about 100) and significantly more torque, peaking below 3000 rpm. A hot rod it's not, but a towing machine it is (or will be!)

Take care,

59toaster · 06-02-2005, 05:34 PM

Quote:

Originally Posted by SafeHarbor

Thanks, guys. I was wondering if the additional weight of the Suburbans is a big factor in choosing it over powerful pickups. How does one determine the rear end ratio? (Take the cover off and count the gears springs to mind...) Is it marked on the differential?

If it doesn't have the gear ratio clearly listed on the glove box sticker then its the default gear. 78 was still the plain old tag with a written option after the option code so very easy to tell what you have.

My guess is in 78 the default gear would be 3.73 if it's a C20 K20 or 4.10 if its a C30 or K30. It would be good for about 9200lb with 3.73. A 4.10 would get you up to about 11k and a 4.56 would get you around 16K.

GM gears will have some numbers on the edge of ring gear. some of those numbers will be in something like 9:37 format. Thats the tooth count on the ring and pinion. Divide the big number by the small number to get the ratio

It should have no trouble pulling anything this side of a D9 Caterpillar bulldozer.

That truck with that engine didn't have much in the way of emissions to begin with. If it had more then EGR, EVAP and PCV I would be surprised. I doubt it even had a Cat. 78 was the first year the 1/2 tons got cats and I don't think the 3/4 and ton's got them till 82.

HOLD on a second!

I just reread you first post. What is this truck (C10, C20 ect). I didn't think you could get a 454 in a regular 1/2 ton and the GVWR your listing is the same as my 75 K5 Jimmy. You sure that door is original tothe truck?

How many lug nuts on the wheels and how many bolts on the rear dif cover? Does it say "Heavy Half" or "Big 10" on the rear fenders? Those were the only Half's that I you could get the 454 in as far as I was aware. The Big 10 was a factory hot rod truck to go against Dodges "Little red Express" and the Heavy half that was really a 3/4ton truck (and the Heavy Duty Chassis E (F44)
and long bed would be standard options for this).

Here are a couple links for you.
These are some good Truck forums.
I moderate this one.
www.coloradok5.com In the main 73-91 forum I have a HUGE links listing at the top of the page for anything imaginable for these trucks.

Another good forum that has a good 73-87 forum is
http://www.67-72chevytrucks.com/

This is a good page that has some Brochures and tech. That blue and White Sub in the header is mine.

http://www.73-87.com/

This guy is in AL. and has decent prices on parts.
http://www.73-87chevytrucks.com/

Attached is a picture of a GM12 bolt R&P I sold. If you look at the top of the ring gear you will see 9:37 that works out to a 4.11 Gear ratio.

Edit: I just read where you said it was a Big 10. Interesting truck you found. It will have a 12bolt axle in the rear.

SafeHarbor · 06-02-2005, 05:45 PM

Hi, Dinoburb,

I know where it's been for the past ten years or so, and the mods were performed before that. It has chromed valve covers, the big manifold, and an
oversize air filter. There does not appear to be a transmission cooler that I could find. The rear leaf has seven springs. The headers look stock, but it needs new mufflers, wires, belts, and hoses. The radiator water looks good and there's no moisture on the dipstick. It was raining, so I didn't get a great chance to look at it. Oh, and the winshield has a big crack (and the radio antenna) in it.

I forgot to look at the brakes to see if the fronts were disks.

The trailer brake controller comes out of the harness under the dash, so I guess it was either a dealer installed option, or the factory REALLY made a wring kit for it.

SafeHarbor · 06-02-2005, 06:09 PM

Hi, Dinoburb,

I'll gladly hold on a second.

Actually, I don't know what model it is, but the glove book sticker says CC10903 for the model and the only Google hits I got when I looked for that were for "Big Ten" and institutional-looking work trucks, which is what this thing looks like. The truck itself says nothing on the front or rear fenders at all. It says "454" in the left-hand grille.

SafeHarbor · 06-02-2005, 06:11 PM

Oh, and those weight numbers are taken from the metal sticker on the right-hand driver's side door jamb.

wahoonc · 06-02-2005, 06:31 PM

Quote:

Originally Posted by SafeHarbor

Thanks, Aaron - that was what I wanted to hear - that somebody tows a 31-footer with a half-ton pickup. I did a search for product literature on this truck, and all could find was that it was called a "Big Ten" model.

Does anyone know where to look for specifications on this truck and where to decode what the installed equipment codes mean? For example, what does "Heavy Duty Chassis E" mean?

Aaron, what's the typical failure mode for these engines? I think this one needs a little work, but it doesn't smoke at startup or stumble when it warms up.

Thanks,

Lamar

PS - My Dakota gets 12 mpg towing the Excella. How much worse could this old monster be?

Lamar,
I am towing with a '03 Ford F150 with the 4.6 V8, we are right at the upper limits of what that truck can handle. We don't tow in the mountains with that setup, if it had the larger V-8 with a 3.73 rear end I would not hesitate to tow anywhere with it. That being said, I have also on one occasion towed the AS with my F150 V-6

It did just fine, didn't set any land speed records but ya do what ya gotta do. BTW both trucks have the factory tow package on them. As far as the short lived 454's the ones we had were in heavy duty work trucks and the first thing to go was the oil pressure, usually via the crank bearings. We had one that lost compression due to scored cylinder walls, never did discover the why on that one. We get 12-14mpg towing the Airstream, with one best of 15mpg when we had a stiff tailwind.

Aaron

SafeHarbor · 06-02-2005, 06:59 PM

Hi, Aaron,

Coming back from Michigan with my Dakota every passing semi was an adventure. The bow wave would push the trailer behind the axles, causing a momentary deflection. Then in front of the axles, causing a deflection in the opposite direction, and the truck would be tail-steered to the left, right where I did not want to be, and quickly to the right. Yuk! My conclusion was that the truck did not weigh enough to control the trailer - ie, the tail was wagging the dog.

This despite a (noisy) Reese dual-cam hitch that I even stopped and had checked and adjusted in Toledo. We also changed the hitch mount to get it up to the user's manual 19 1/2 inches. (Young's RV in Perryville, OH - NICE folks and a fair price considering I kept coming up with things to ask the mechanic and new stuff to do to the trailer.)

And going up the hills in KY, TN, and N. GA in third gear at 3600 RPM @ 60 mph was not comforting either.

Thank you for the additional info. The oil pressure on this one looks good, and I don't think it's ever had to work hard for a living. I think the former owner used it for backing a bass boat into the lake, and the most my dad's done with it is bring home 2800# of firewood, or so he claims.

SafeHarbor · 06-02-2005, 07:21 PM

Hi, 59toaster,

Thanks for the great links and information. It's YOU that I'll hang on for a second and you I should have addressed the rest of the answer to. I'm doing some interesting reading at the sites you mentioned and will be for a while tonight.

Thanks!

Lamar

SafeHarbor · 07-06-2005, 12:03 PM

Hi, folks,

I haven't been able to pick this old monster up (had truck troubles of my own to overcome), but a breakdown of the serial number, the GVWR, and some Pickup, Van, and Four-Wheel Drive articles indicate that the truck is a 1976 Big 10 model, I think.

http://www.73-87.com/7387info/Road_Test_7380.htm

59Toaster, does that jibe better now with what you thought?

Thanks,

Lamar

the ponz · 07-06-2005, 12:19 PM

Quote:

Originally Posted by SafeHarbor

PS - My Dakota gets 12 mpg towing the Excella. How much worse could this old monster be?

My father's 1979 454 1/2ton suburban got 9 mpg going up hil, down hill, pulling a 26' argosy, or simply coasting in neutral. In fact, I believe if you left the engine running while refueling, the truck would draw on the pump. BUT what a great truck!

jim8860 · 07-06-2005, 12:58 PM

The "Big-10" whas a nick name for that truck.If you are looking at that same truck shown that may be a bit bumpy to tow with. My experance with a Chevy "Step Side" that it was not a great tow rig, but looking at the "specs" on the truck it has all the right parts. I would like to buy that truck and restore it becuase it a real piece on Chevy history and a real cool tuck. Try to get all the stock parts if they are still around. Good Luck Jim

SafeHarbor · 07-06-2005, 05:21 PM

Hi, Jim and Ponz,

From what I can tell, it has the same heavy duty suspension (F44), but it's got the GVWR of the half-ton. Anyway, I'll find out next week. God willing, I'm going to pick the thing up next week.

59toaster · 07-06-2005, 07:55 PM

Quote:

Originally Posted by SafeHarbor

Hi, Jim and Ponz,

From what I can tell, it has the same heavy duty suspension (F44), but it's got the GVWR of the half-ton. Anyway, I'll find out next week. God willing, I'm going to pick the thing up next week.

Yeah they did some weird stuff in the late 70's to "circumvent some of the emissions requirements that were just being passed. A late 70's 454 was making the power of a 70 350. They were having to dump the compression to overcome detonation problems with unleaded fuel and the cats were very inefficient at that point and really sucked the power out of the motors.

If the suspension stiffness is an issue you can always put a set of 80's Half ton springs on it and soften it up. The late 80's they made HUGE improvements in the springs including friction reducing pads and relaxed spring rates to make them ride better.