The Stovebolt Site Forums The Parking Lot Big Bolts What is my Engine?

I got a Viking 2 ton back in the summer, and the truck just seems really sluggish. Combine this with the facts that it will crank forever, refuses to run hot or cold (depending on adjustments), and I hear one of the cylinders fire intermittently, has led me to believe the engine is worn out.

Unfortunately, I can't seem to ID the engine. Due to a parts kit I installed, the casting number on the transmission, and the presence of a quadrajet carb, I can tell you that it is a Chevy SBC, built around the early 60s. I looked at the block, and I believe I have the stamped numbers to ID the engine, but Google isn't being friendly about it.

12K541654 T1115CTL

If anyone can tell me anything about this engine, I will be grateful.

According to this suffix code chart, "CTL" means you could have a 350 or a 400 small block from the early to mid-1970's. A 400 will have a very large harmonic balancer with a thick balance weight cast into part of the outer ring and a weight on part of the flywheel if it's equipped properly.

http://www.nastyz28.com/gm-chevy-codes/chevy-engine-codes-suffix-3.php

It doesn't appear it's an original equipment engine for the vehicle. What year is the truck?
Jerry

The truck is a 1958 Chevrolet Viking,built in the St Louis Truck Assembly factory, sometime early in the year(I forget the exact date) this one is a grain truck, and as such, is a farmyard survivor. This truck's vin ends in 41, so it came with the six cylinder Thriftmaster. Combining this with the 70s-80s era gas pedal, extremely faulty throttle connection, And the farm connection, I can only guess, but I bet the farmer killed the six, and stuffed the v8 in its place. The front mounting brackets, while solid, are clearly homemade.

Don't quote me on the engine stampings; the only way I could even hope to read them was by spraying a thin coat of brake cleaner on the block, and reading the refractions.

On a separate note, does anyone know if the 2-speed 15000 rear axle came in different pinion and ring ratios? This truck is absurdly slow, and it has the 22.5" wheels, so my only hopes are to install a "transfer box" between transmission and axle, or change the final drive speed.

how slow is "absurdly slow"? My '55 2-ton would "top-out" at 45 M.P.H.,on the "Lo" side of the rear end. the "Hi" side was 55,(Happy),60 M.P.H.,Tops. 9:00X20:00's Is yours a 1-1/2-ton,with a single-speed rear end? If so,if you change to a vacuum 2-speed,you'll need to find a truck with a complete system,including the switch,(located on the transmission,follow the cable on the shifter),and the speedo. adapter,located behind the instrument cluster. try and save the 2 lines that "run" the length of the frame from the switch,for a pattern,if too rusted to re-use. If you could find a good electrically-operated 2-speed,you'll only have a couple of wires to install,instead of plumbing all of the vacuum lines.

Casey 59,

Welcome to the Stovebolt

You didn't tell us what series truck you have...40, 50 or 60? Knowing this will help us give you correct info.

FYI, the Chassis serial number located on the door post will not tell you anything about what engine came in you truck other than the "V" prefix saying it had a V8.

Mike B

I don't exactly know how fast it goes(it's too tempermental to even try highway) but everyone keeps saying that 55 is the limit, it apparently can go 60, but I'm sure that's pushing it. I want the truck to drive comfortably around 65-70mph (it's a lot of highway between me and pretty much anything).

I know that the body styles changed every few years, but I also heard mentioned that the frames were very consistent into the 70s. I'm wondering, were the axles the same? Kept similar enough that parts can be exchanged? Or did Chevy respond to the low gearing by installing transmissions with a serious overdrive?

To be specific, the truck is 6A 58S123241. A Chevrolet Viking 6100 built in 1958 in the St. Louis plant, on January 23rd, if the vehicle info kit is to be believed. This truck is equipped with a mystery V8 coupled to a Muncie SM420 with PTO bed lift, driving a 15000# 2 speed vacuum operated rear axle. The truck came with the Deluxe air handling system, and a driver's side spotlight. these seem to be the only luxuries; the radio is just a plate inserted in the dashboard..

Casey,

Sounds like you got the serial number almost right...

6A = 6100 series (132" wb)
58 = year
S = St Louis Plant
123241 = unit number starting with 100001, so you have the 23241st unit out of St Louis

The actual build date is not available from the chassis serial number.

This truck would have had the 261 6-cylinder as standard issue with the 283 V8 as optional.

The 2-speed rear is a 6.40/8.72:1 ratio.

Are you running 8.25 x 20 or 9.00 x 22.5 tires?

Making the truck run 65-70 on the hwy will take the truck beyond it's safe zone. The steering and brakes were never designed for those speeds. Your SBC should push you along nice in the upper 50's - low 60's mph range.

If you really need to go 65-70 you will need to swap out both axles for better gears and better brakes. My '57 Fire Engine will run 65 mph on a flat road and has been 70 going down hill, but that's WAY over my confort level...it gets real squirrelly at that speed.

Rear axles are easy to swap, for the most part they are all the same width. The front axles are a different story, you'll need to measure and search for a good fit.

Mike B

So the axles, but not their parts, are interchangeable? The brakes are a valid point, and I have been looking into disc brakes for a bit now, but how exactly is the steering a problem? Is the design so poor it can't hold rigidity at those speeds? Straight up swapping axles is a bit much, could the hubs be replaced instead? Would switching to Daytons be seen as a major improvement over the 6 lug Budd?

I also have a lead on a 70s-80s GMC 6500 with an electric 2 speed axle. The rear axles look identical. Any ideas if parts are interchangeable?

Casey, The easiest way to increase your speed and drop your RPMs is to install an overdrive unit between the bellhousing and transmission. Look up a company called Advance Adapters. They have a Ranger Torque Splitter that is only 7" long, 27% drop in RPMs, bolts to the bellhousing and your transmission bolts to it. Extremely easy and your speedometer remains unaffected because it mounts before the transmission. You will just have to move your hole in the floor 7" back for the transmission shifter. The unit that they sell does need to be shifted manually. If you're interested, I have one for sale that has an electric shifter that shifts just like a 2 speed rear end with the shift switch on the transmission shifter. Asking $800. DaveV

Dave,

It's going to be a while. It's far too cold out here in the Midwest to try working on the truck. I'm just trying to figure out where I'm going, before I start the journey.

This banter on the gearing on my truck is bringing many valid points to light, but it is really secondary to the engine. If I don't know what I got, this truck won't move, rendering the top speed a moot point.

The engine is most likely a SBC 350 or 400, and apparently the harmonic balancer is larger on the 400. Does any one have pictures to compare the two? All that Google images is giving me are stock photos.

DaveV,

Did you ever have that unit installed?

How does the speedometer stay calibrated if it's ahead of the trans?

The TF trucks just hang the trans off of the back of the bell housing (no rear crossmember). Is you overdrive unit designed to carry itself and the transmission without supporting either?

Mike B

Casey,

The steering system if all new/rebuild should be fine at high speeds, it's just above what I'm comfortable with, it's not a poor design.

I'm not aware of any direct bolt on front disc brake setup for the medium duty TF trucks. The only way I've heard of others doing this is to replace the axle hub to hub.

After you get the front disc brakes done, find a modern rear with the gears you want and disc brakes and swap it all out. Replacing the entire rear is not that big of a job...cut the U-bolts, cut the brake line and disconnect the U-joint and the rear is out. Then slide the replacement rear in, bolt it to the existing springs with NEW U-bolts, connect the brakes and modify the U-joint and driveshaft to fit.

Whats the gear ratio on the GMC 6500 rear?

What's wrong with the 6-lug Budd's? If you swap in new modern axles (with disc brakes) you will more than likely end up with a different lug patteren anyway.

No matter what SBC you have it will have more HP than the original 160 HP 283, so you should be fine.

Mike B

The truck reads 9053 miles, so the steering will be checked, but I doubt it is an issue.
The front hubs should be removable from the spindles without spoiling alignment, and also allowing the front bearings to be replaced (the truck is at 9k miles, but it was a farm truck, I'm not gonna risk that). The rear axle is a simple affair as well: the plate that holds the driveshaft and pinion actually holds the entire assembly, minus the axle shafts. Pull the shafts, and remove the differential assembly, swap in new, reinsert shafts. I could even go to electric, but I suppose actuators have a common mount.

The brakes are a point of concern, but I have heard of others adapting f550 brake systems to fit six lug Budds. If nothing else, I'll build new brackets. Don't worry, for me it's not built until it is massively overbuilt.

I'm not sure about the 6500; the driver side door is seized in the frame. I took a glance underneath, and the axle looks the same, barring fin casting alterations. It should be a straight swap, assuming the yard will let me touch the truck.

I have nothing against Budds, except that I have found 1 8x22.5 rim in my entire area, and I have a single one piece rim. Not exactly a reassuring fact.

The engine's power is no concern whatsoever; that is why I want to gear up. But if I don't know the engine, I won't know what parts to get for it.

Casey,

Truck rear 3rd members (pumpkins) are not universal. If the GMC rear has electric shift it's more than likely an Eaton, the rear in your truck is a Corporate GM rear, not the same.

Taking the rear out of a junk yard truck without knowing the gear ratio could be a BIG waste of time and money. Slide under the truck with a scraper and wire brush and find the stamped numbers on the front or top of the carrier housing or on the front end of the pinion shaft.

I'm confused...what's this "single one piece rim" you're talking about (22.5's are all single piece)?

Post some pictures so we can see what you have!

Mike B

Mike B, Yes I had it installed in a 74 1 ton truck that was set up for pulling a triaxle trailer. It allowed me to split shift each tranny gear giving me an 8 speed truck with overdrive. I might not have been clear on the speedometer. The overdrive unit is ahead of the tranny so the speedo hookup is still on the tranny giving correct readings. Some overdrive units are after the tranny so the speedo is only accurate in low range. The tranny crossmember does need to be slid back 7" and driveshaft shortened 7". DaveV

Alright I give up. How do you post pictures?

DaveV

TF transmissions don't have provisions for attaching a crossmember to them, they just hang on the bellhousing. That might put a lot of strain on the OD case if it's not designed for all of that extra weight...



Casey,

Get a picture hosting web site like Photobucket. Up load your pictures there, then cut and paste the link here...

Mike B

Here is the pictures on the truck;

https://drive.google.com/folderview?id=0B6Aw4aYru4MTaFluVE9la1hHUU0&usp=sharing

The pictures of the wheels point out the one one-piece rim, and the three-piece that makes up the rest.

I took a picture of the harmonic balancer, is this the style that the 350 has, or the 400?

Casey,

Nice truck!

Looks like all of your tires are 20" which makes them tube type with multi-piece rims. The one's with the wide band in the middle are the Firestone RH-5 rims that are known as the "widow makers", they are actually 2-piece. The one that you think is 1-piece on the right rear looks like a lock ring or split ring type (look on the inside and see if there is a separate ring around the bead). The only tubeless tires from the 50's would be 22.5".

Nice to see they installed the Deluxe Heater and Passenger Side Sun Visor.

I'd also question the 9K miles...my guess is it's 109K. Things that make me think this are the original engine is gone, seats worn out, pedal pads are worn or gone and the interiors been repainted.

What are your plans for the truck?

Mike B

Forgot to ask...did that LCF Hood come with the truck? Looks like 55 or 56...

Mike B

Craaaap, could've sworn they said 22.5... Would installing 22.5s mess up the speedometer, or even make it more accurate?

I was also left with a spare visor mount: I'm gonna put on a driver's side visor, over the door, if I can.

I suspect the 9k to be correct. Remember; this is a grain truck, it would only see a few hundred miles a year. My grandpa was a farmer, and his(and my dad's)method of repair was "fix it so it works another week." Of course, if it's "working", why change it?

The V8 wasn't the only indicators of a half hearted repair: the alternator was connected to the system with romex - residential wire. The rear hitch was welded on using a stick welder, and they went too cold, yet again. The wiring on the back was crimp on connectors, electrical tape, and whatever bits of wire that could work. The interior paint has brush strokes; they took the seat out, and the rest was slathered. The door panels, strike plates, and hinges, had more random hardware than original fasteners. The truck got flooded at some point: their response was drain the engine and refill. They neglected the rest. The transmission needed everything but the gears replaced. The lift power assembly literally floats between the frame(it is held in position by the pump's driveshaft). This truck most likely led a light use, but brutal life. It is rather common to find grain trucks which barely hit 100k, and many others fall short. They tend to suffer from lack of use(the hoses are rotted and cracked; brakes seize to the drum; bad gas; the oil drains from the top end, resulting in increased wear, etc.).

I want to restore and upgrade this truck, and keep it until I retire. An ambitious goal to be sure, since I'm only 22 years old. It will be a general hauler.

The pictures you see of the truck surrounded by others, were taken at the lot I bought it from. Considering the rest of it, it was either original, or was replaced within the first few years.

Casey,

If you have 8.25 x 20" tires the exact replacemant in width and diameter is a 9.00 x 22.5" tire. The Tubeless 22.5's were made to be the replacements for the Tube Type 20".

You won't have any speedometer issues as long as the rear tires stay close to the same diameter.

Does the LCF Hood still have the emblem attached...what year is it?

Mike B

The hood has the badge on the front, though it's cracked.

I'm not sure I follow you, what exactly do you mean by 'LCF hood'? is that the indent down the middle, or some kind of limited edition affair?

The truck is a 1958.

Sorry Casey wasn't trying to confuse you, LCF stands for Low Cab Forward. They look just like your truck, but the have a short hood and the wheel opening is cut back into the door. Click on my 1956 9200 below my signature to see what they look like. The hood in the bed of your truck looks like the short hood. It also looks smooth across the top making it a 55/56, am I right?

Mike B

This 1958 is not a LCF truck (Low Cab Forward)
This 1958 is a LCF truck. It has "snub-nosed" hood, so to speak.

Ah, I see now. Hate to break it to you mike, but the grille and hood didn't go with the truck, and I didn't really stop for a good look. They probably still have it, if you're interested.

Doug's four wheelers, based near Pella, Iowa.

Thankfully I don't need it, but would be ashame to see it get scraped. LCF hoods are not being reprodeced AND the hood emblems are different than the conventional trucks making them VERY rare.

Mike B