Big John: 1972 C30 2WD dually w/ 11' dump bed

Lurch830

Lurch830

messin' with sasquatch
Joined
Mar 1, 2007
Location
Wilton & Albemarle, NC
This project is named for my grandpa John, but people call him 'Big John' like the Jimmy Dean song. This will not be a restoration, but more of a freshening up to use as a farm/hunting truck.

The weekend before Thanksgiving 2018 I talked my grandpa into "selling" me his '71 C30 and I wanted somewhere to document getting it running again since it will be a slow & cheap build and I'm hoping this keeps me from forgetting things. I put "selling" in quotes because I still haven't seen the title or the keys & every time I bring it up he tells me I don't have the time, I don't know what I'm getting into & I'm making a mistake. I "bought" it for a few reasons:
*been in the family for ~30 years & only "cost" me $300
*has hydraulics that I'm hoping can raise/lower an ag drill
*give me the inspiration/motivation to work on my crawler again

Determined to be just as stubborn about it as my grandpa is, I'm going to start working on it with the hopes he caves & signs over the title. If he doesn't, at least he'll be able to use it around his place. I'd like to get it safe & reliable before getting the title & putting it on the road; after that I'll worry about doubling the fuel mileage (currently 7mpg), getting all the gauges working & updating things.

Plan is to build this thing in phases. Phase 1 is clean, disassemble & inspect. I'm not too sure on its history, but I've got to start somewhere! I've been told its got a rebuilt 4 bolt main 350 V8 with a mild cam, but the last time it ran (~9 years ago?) it didn't sound mild to me. The starter was rebuilt the last time it ran & I remember the brake lights didn't work, but when you pushed the brake pedal all 4 turn signals lit up. Its got a 4 speed manual transmission (sm465 or sm420?) that seems to go in each gear with a PTO driven hydraulic pump that operates the bed. I've also been told the rear axle is geared 5.XX:1. I know it doesn't have a battery, the stock fuel tank leaked and was replaced with a removable boat fuel tank & it looks like its been used as a trash can while my grandpa is mowing. I moved it from where its been sitting for almost a decade to tinker on it a bit during weekends since I go home to hunt anyway. First thing will be to power wash it so I can inspect everything. All the cab corners feel solid, but the rocker panels have some rust at the pinch seam, the front of the fenders are rusted & I found a small hole in the floor board. I plan on cutting out all the cancer & priming at a minimum to stop it from getting worse, but I'll be leaving the patina. All the fluids will need to be changed and the brakes rebuilt; as well as new plugs, wires, hoses & belts.

Phase 2 will be to drive it around & use it on grandpa's property until I can get the title. Phase 3 will be to change out the transmission for one with overdrive (as long as I can find one with the same PTO), add rear wet lines for ag drill connection, reupholster the seat, new weather stripping to seal up the cab/windows, change the bed up a bit, upgrade the lights, change out rear axle (better gear ratio, limited slip/lunchbox locker & disc brakes).

How it sat before I moved it this weekend:
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An NV4500 is about your only option for a 5 speed with OD and a PTO. Might as well do a Cummins swap too :D
 
Croatan_Kid said:
An NV4500 is about your only option for a 5 speed with OD and a PTO. Might as well do a Cummins swap too :D
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Don't the NV5600/G56/ZF5/ZF6 all have PTO options too? I know the new autos do. PTO is a pretty common option, even with todays fancy trucks.
 
I love it! You might catch some hell finding grill parts though.
Very cool truck.
 
Croatan_Kid said:
Might as well do a Cummins swap too :D
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Negative ghost rider! Hoping to get it driveable around the property for under $1k & if/when I get the title get it on the road for $3k-5k. I looked into gear vendors over/under drive, but $3k blows the budget.

jeepinmatt said:
Don't the NV5600/G56/ZF5/ZF6 all have PTO options too? I know the new autos do. PTO is a pretty common option, even with todays fancy trucks.
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I'm not going to do anything about the transmission until I get the title, but I'll definitely look into options for when that time comes (going to keep it manual).

shawn said:
Yup. Dunno for sure about the ZF6, but the rest do.
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Things like this are partially why I created the thread, most of the people on here know way more than I do & I'll be putting that to good use when the time comes!

XJsavage said:
I love it! You might catch some hell finding grill parts though.
Very cool truck.
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For driving around the property, I'll leave the current grill. Once I get the title, I was thinking of replacing with a DIY expanded metal grill w/ a 40" LED bar I have laying around wired with the high beams.
 
jeepinmatt said:
Don't the NV5600/G56/ZF5/ZF6 all have PTO options too? I know the new autos do. PTO is a pretty common option, even with todays fancy trucks.
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Sure they do...but which one of those bolts up to or even came behind a GM motor?

Edit: There was a GM ZF6 that came behind the Duramax, but good luck finding, affording, or getting parts for one. Kinda like an NV5600.
 
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Croatan_Kid said:
Sure they do...but which one of those bolts up to or even came behind a GM motor?

Edit: There was a GM ZF6 that came behind the Duramax, but good luck finding, affording, or getting parts for one. Kinda like an NV5600.
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But for a truck that big and heavy, if you're going through the trouble of a trans swap, why stick with a 350 gasser? :D
 
I already suggested a Cummins swap and he shot me down :( Maybe he'd rather do a Duramax swap :huggy:
 
jeepinmatt said:
But for a truck that big and heavy, if you're going through the trouble of a trans swap, why stick with a 350 gasser? :D
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Just for running around or play, the 350 is fine! I drove a C50 or 60 [forgot] Fuel oil delivery truck with the 350, & 4 sp. Don't know the gearing, but that sucker got around good. Just as the older Fire trucks did. GMC s & Chevy's with 283 s & Fords with 331 s. Slow by today's standard, but dependable & easy to work on!
 
jeepinmatt said:
But for a truck that big and heavy, if you're going through the trouble of a trans swap, why stick with a 350 gasser? :D
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The trans swap is almost like a last ditch effort to get better fuel mileage. My brother was the last one to drive it on the street while putting a new roof on his house & logging his property. He told me empty it gets 8mpg & loaded it gets 6mpg. If I'm driving this thing on the road between Stanly & Cabarrus county I'd like to get it closer to 15mpg. Depending on what its geared now, I'm thinking 3.73 or 4.10 would almost serve as a 0.7:1 overdrive which should break me into the double digits for fuel economy.

Croatan_Kid said:
I already suggested a Cummins swap and he shot me down :( Maybe he'd rather do a Duramax swap :huggy:
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Honestly if I was restoring it, I'd put a modern drivetrain (likely diesel) in it and I won't totally cancel that in the long term future, but its not in the plans now.

rodney eppes said:
Just for running around or play, the 350 is fine! I drove a C50 or 60 [forgot] Fuel oil delivery truck with the 350, & 4 sp. Don't know the gearing, but that sucker got around good. Just as the older Fire trucks did. GMC s & Chevy's with 283 s & Fords with 331 s. Slow by today's standard, but dependable & easy to work on!
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That's exactly what this will be used for, just running around/having fun/chasing bambi. Plus it'd be nice to have a long bed again!

rodney eppes said:
Where has the truck been sitting? Sure looks familiar, but most of those trucks Did look the same! Blue was the common color.
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If I told you, I'd have to kill ya!
In Stanly County between Albemarle & Aquadale, but a pretty good ways off the road.
 
Spent some time during weekends cleaning it up & looking for the key(s)/title. Found out from prior registrations that the truck is actually a '72 model & has a camper chassis (no idea what that actually means). Also has locking ring wheels which I want to replace with a modern 8x6.5 wheel; I was hoping H1 wheels with military takeoffs would fit, but they're too tall. The chipboard glove box has been destroyed by mice/bugs, but I found 4 railroad flares from 1980 in it which I admittedly thought was dynamite at first. Flares were no good (even tossed them in a bonfire for good measure) & I haven't spent too much time on it since I bought a house in February. Also found out the fuel line burst at one point which sprayed fuel on the exhaust manifold and then caught on fire. That explains the paint damage on the passenger side of the hood & the bad wiring.

Most recent development...apparently one of my grandpa's friend's grandsons (8-10 years old?) saw the dump truck and asked about it. That prompted a phone call from my grandpa asking if I really wanted the truck. Most of which was him trying to convince me I don't need it (true) and I don't know what I'm getting into (partly true), but I finally got the point across that I want it & I think it'd be cool to own a ~50 year old truck that my grandpa got in the 80s. So I paid a visit to him this weekend, finally found the key & he signed the title over to me! Convenient thing is Brothers Trucks is having their Spring Savings sale so I put a list together of stuff to order.

Plan now is as follows:
Buy stuff on sale...30% savings FTW!
Pull the plugs, put a little oil in the cylinders & rotate by hand
~redneck compression test while the plugs are out
Hook up to a battery & turn over with starter
Check/Change fluids in the trans & rear end
~check gear ratio
Troubleshoot/repair anything that prevents it from cranking, running, driving and/or stopping
Put on new plugs, wires, belts & hoses
 
shawn said:
Yup. Dunno for sure about the ZF6, but the rest do.
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They do, but as @Croatan_Kid said they are rare for the Chevy form and the Chevy version is less desirable than the Ford.

I personally would ditch the drivetrain, in favor of an LS and nv5600. Diesel swaps are just way to much $$$$$$.
 
Chris_Keziah said:
I personally would ditch the drivetrain, in favor of an LS and nv5600. Diesel swaps are just way to much $$$$$$.
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Gonna keep the current drivetrain for now...supposedly it has a rebuilt or aftermarket engine with at least a cam.
 
I would recommend checking with Dave's Truck Parts if you need anything... Not super close for you, but great guy to deal with and knows his stuff. He has been doing it long enough that he knows where to get the parts that work well. Home
 
CarolinaHD said:
I have a GM 2wd zf6 with a solid flywheel in the basement.. :driver:

I know it's just a farm truck but be careful about ordering stuff through brothers, LMC, etc as most of the fit and finish is not very good. Also be sure and check out the 67-72 truck forum. Lots of good, used OEM parts for sale.

The 1947 - Present Chevrolet & GMC Truck Message Board Network - Powered by 67-72chevytrucks.com

My 67 c50 has a 292 l6 in it, talk about slooooowwwwww.
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I've been using that site for a lot of info, but haven't signed up yet...guess I need to do that! As far as the fit/finish, is that for patch panels/sheet metal or everything? The stuff I had earmarked to order tonight is wiring harness, vent window seals, gas tank sending unit, gas tank grommet, gas cap, seat cover, headlight wiring harness, 7" halogen headlights & maybe a new glove box insert.

paradisePWoffrd said:
I would recommend checking with Dave's Truck Parts if you need anything... Not super close for you, but great guy to deal with and knows his stuff. He has been doing it long enough that he knows where to get the parts that work well. Home
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I'll check it out...thanks!
 
Lurch830 said:
The stuff I had earmarked to order tonight is wiring harness, vent window seals, gas tank sending unit, gas tank grommet, gas cap, seat cover, headlight wiring harness, 7" halogen headlights & maybe a new glove box insert.
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I've ordered a lot through classic heartbeat parts they're a vendor on the forum as well.

chevy parts - chevrolet truck parts - chevy truck parts - gmc truck parts - classicheartbeat.com - - - Classic Heartbeat Truck Parts

I would get the gas tank related stuff from heartbeat, all weather seals from precision industries, and the rest should be good from lmc.
 
Didn't get a lot done over the weekend or Tuesday afternoon when I was in the area, but some progress was made:

A guy I know in Shelby is restoring a '67 C10 and ordered a stock replacement fuel tank before deciding to put it under the bed & ordered one of those. He's been moving the stock tank around his garage for a while & its in his way so its earmarked for me. He said he'd trade me even for grandpa's old tank that was rusted out just for the filler neck so his would look factory. Spent about 1 full day going through the hanger, barn and storage sheds before coming up empty handed. Grandpa thinks he scraped it years ago, but I thought there was a chance he hoarded it away. Also, apparently there is a different tank if you have a '67-'70 (no smog) vs a '70-'72 (w/ smog)...but for the budget friendly price of free, I'll take my chances! My buddy tried talking me into getting an under bed tank, but since this is a dump bed, there is a hydraulic cylinder in the way up front & with the way it pivots plus where the rear axle is, I think it may get crushed. I do like the idea of getting it out of the cab for venting...may coat the thing inside & out to prevent fumes.

Cleaned the windows & mirrors since that's really critical in getting the thing running, broke the plugs loose, and pulled most of the floor mat. Windows cleaned up well since you can actually see through the cab now...grandpa joked that I'd just rolled the windows down! Plugs came loose with little effort since grandpa is a firm believer in lithium grease. I couldn't unbolt the rear seat brackets without banging up my knuckles & cussing up a storm, so I'll have to go back with ratchet wrenches.
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Also got some more info on it...he did paint it years ago with Ford Blue tractor paint when he painted his 2810, the motor rebuild consisted of a "pulling" or "power" cam (kept switching between the two), bored the cylinders (he can't remember how much) and undersized rods?, and got a lesson in operating the PTO/hydraulics. Two rules he made clear are don't get under the bed when its up without a brace (on the list to build) & don't lower it at once, but bump it since the pressure relief valve drops the bed instead of a controlled lowering. And the PTO cable is made by dana/spicer.
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I told him my plans for keeping the patina & he said "I'd knock the loose rust off, prime it & paint it with tractor paint. But it's yours now so do whatever you want." So I'll be correcting any major rust spots this way & leave the patina/surface rust. Also told him I'll eventually trailer it to my house to work on it more & got "Best thing you could do is stop at a junkyard on the way and sell the damn thing!"
 
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That is a great looking rig, and a good solid start as far as I am concerned. For mpg, I would suggest tossing on one of the readily available tbi setups on the market these days, I would bet you realize more fuel economy with that, then with an OD trans. swap.

As someone who daily drove a 1970 K20 for a few years, I would also put a hyd. clutch HIGH on the list of to-do's.....you will be surprised how quickly your left hip and knee start to hurt.

When you get a chance, crawl under the rig and snap a picture of the rear axle....it SHOULD be a D60, but it MIGHT be an Eaton HO72. The Eaton will have a round rear cover and a drop out center chunk / third member like a ford 9". If you have one of those, the third member is easy to swap in and out (just don't drop it on your face!). I think the highest gear that came in the Eaton is 4.10 (rumors of 3.92, but I have never seen a set). Open third members are cheap, I think I sold my spare with 4.56's for $100 a few years back. They were optioned with lockers, but they can be hard to find, it took me 2 years to find a locked 4.10 setup.
 
I'll keep the tbi & hydraulic clutch in mind, thanks! I've already had 2 surgeries on my left knee for torn cartilage...unfortunately nothing with it surprises me anymore.

I think the rear axle is the HO72...I keep meaning to take pictures & measurements but never think about it when I'm working on it.
 
As said above 67-72chevytrucks.com will be your friend, although I believe I have seen an HO72/52 for sale here once or twice.

The third member / hogs head from a 3/4t (HO52) and a 1t+ (HO72) will both fit in your axle. HO72 is suppose to have a load bolt on the drivers side of the hogs head to put load against the ring gear.

If you have had surgery on that left knee already, I would definitely recommend looking into a hyd. clutch, that truck probably has either an 11 or 12" clutch, with a VERY heavy pressure plate, being as tall as you are in a regular cab, the ergonomics are going to be even worse (you almost end up pivoting at your hip with your knee bent).
 
What spline count are those axles? I have a random Detroit locker laying around and it's something like 16 or 17 spline. A guy sold it to me thinking it was for a 14 bolt.
 
Croatan_Kid said:
What spline count are those axles? I have a random Detroit locker laying around and it's something like 16 or 17 spline. A guy sold it to me thinking it was for a 14 bolt.
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17 Spline, some people swap in 14 bolt shafts with a detroit locker for a 14 bolt....I can't remember all the details for the swap though.
 
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