C60/ Medium Duty Trucks

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highdesertrange

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mike
Truck Year
1978
Truck Model
k30
Engine Size
454
well I think the engine has been replaced with a 60's small block. what size is the harmonic balancer small or large. short wp and small balancer is 60's. if the truck sat for that long the tires are going to be junk. it is cool and I do like those trucks. good luck. let us know what you do. highdesertranger
 

bucket

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Truck Year
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Truck Model
K5 thru K30
Engine Size
350-454
All the tires are still holding air and they don't appear to be dry rotted either. I know they are old and 'should' be replaced, but they wouldn't top my list of things to replace.

It's anyone's guess how long the truck has been sitting too. The owner thought he last drove it 6 or 7 years ago, but the inspection sticker expired in early '98. He very well could have been driving it after then with Farm Use tags.
 

RetroC10Sport

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2001
Truck Model
pontiac aztek
Engine Size
3.4
well I think the engine has been replaced with a 60's small block. what size is the harmonic balancer small or large. short wp and small balancer is 60's. if the truck sat for that long the tires are going to be junk. it is cool and I do like those trucks. good luck. let us know what you do. highdesertranger

A lot of that stuff was actually used on big commercial trucks and buses well in to the 80s and even 90s.
 

highdesertrange

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1978
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k30
Engine Size
454
yes I know but not the small balancer engine. highdesertranger
 

bucket

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Truck Model
K5 thru K30
Engine Size
350-454
I will look at the balancer tomorrow when I'm there... unless it's still frickin raining and I spend all day at the cabin again.

And I never thought to look in the glovebox for a SPID.
 

towjoe

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Lafayette,IN
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joe
Truck Year
78,80,81,81,86,88,89
Truck Model
K30's or V3500's
Engine Size
6.2, 454
There should be a vacuum booster under the cab that the master cylinder line runs to and to each axle from it. As I said before there's a lot of strange options when they built these trucks and balancer/ engine could be correct. Had one few years back I was cutting up that had a 400 sb in it. Guy swore his dad had never swaped motors and engine was correct of the year truck by numbers. I used to scrap a lot of the old c40-c70's years ago, there was one in every farmers field it seemed like. Worse thing you run into is the critters eat all the wiring out of them in the case of this one. That's why most of them got scrapped because they weren't worth rewiring.
 

marks86

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Latham, NY
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Mark
Truck Year
1986
Truck Model
K30
Engine Size
12v Cummins
Picture of gauge cluster PLEASE a lot of those had diesel tachs:gr_grin:
 

bucket

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K5 thru K30
Engine Size
350-454
It's just a basic cluster with no tach.

I didn't notice any chewed electrical either, but I also didn't stick my head up under the dash. There just was chewed nutshells everywhere on the floor and a fairly strong urine stench. It actually smelled like my Camaro I got that had racoons living in it, but after looking, the truck wasn't nearly as dirty as the Camaro.
 

DoubleDingo

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Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Grandpa had a 63 GMC like that. It had a 283 or 327 in it. Not a bad truck. It could come in handy for sure. If I end up with some acreage I would want to have a truck like that.
 

bucket

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Truck Model
K5 thru K30
Engine Size
350-454
The glovebox contained various nutshells and a SPID:
 

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bucket

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Truck Model
K5 thru K30
Engine Size
350-454
According to the SPID, the truck actually has a 4 speed, the knob must be from another truck. I have read that the big truck 465 trans was basically the same as the pickup version, but had some differences like a bigger input shaft. Now I wonder if my GMT 400 shift tower and new shifter will fit the trans in this truck.
 

Stewzer55

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Stew
Truck Year
1988
Truck Model
R30
Engine Size
350 TBI
And a 350 too, I wouldn't be surprised if its original. Medium duty trucks still used mounts similar to the tri-five cars too for the engine.
 

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