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73-87 Chevy _ GMC Trucks => Members Rides => Topic started by: Jason S on October 29, 2011, 12:34:07 pm

Title: 1973 GMC K2500 Camper Special
Post by: Jason S on October 29, 2011, 12:34:07 pm
Here are some photos of my '73 GMC K2500 Camper Special.

Prior to propane install.
(https://lh4.googleusercontent.com/-iRMfMValM2Q/TrGm62GzOSI/AAAAAAAAACg/W5p5cdmS7EI/s800/SAM_0652.JPG)
(https://lh5.googleusercontent.com/-TkyaxA6W2_w/TrGm4xkkUBI/AAAAAAAAACc/brLZQG3yuRg/s800/SAM_0653.JPG)
(https://lh5.googleusercontent.com/-JhrJuQZSV8Y/TrGm95gwQlI/AAAAAAAAACk/1wIt7Yt3Ehs/s800/SAM_0651.JPG)
(https://lh3.googleusercontent.com/-5y38eul2wUA/TrGm0TB8AUI/AAAAAAAAACU/iXbBi4ISDgA/s800/SAM_0654.JPG)
Title: Re: 1973 GMC K2500 Camper Special
Post by: thirsty on October 29, 2011, 01:20:19 pm
Great looking truck. That color is awsome for a truck like that.
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jason S on October 29, 2011, 01:48:48 pm
Thanks Thirsty.  That is the factory color, I think it's called Green Gold Metallic.

The bed is a later mode that went on after i slid off an icy road coming back from a hunting trip. While i kind of miss the flush mount fuel filler caps, I don't miss the fuel streaks that seemed to be a regular occurrence.

Here are some more photos after the propane install.

(https://lh4.googleusercontent.com/-szvIpz5oK74/TrGl04rLUoI/AAAAAAAAABM/FMdRkBFPCCw/s800/DSC00600.JPG)
(https://lh5.googleusercontent.com/-1wzAygnoksQ/TrGly2NctWI/AAAAAAAAABI/TA42yYWyAsc/s800/DSC00601.JPG)
(https://lh3.googleusercontent.com/-grwkG3wT98o/TrHIAVkU1eI/AAAAAAAAADo/h9-aOyT5HMA/s800/DSC09446.JPG)
(https://lh5.googleusercontent.com/-1mNOkMhHWEs/TrGmgX0mAVI/AAAAAAAAACM/hMRKIz-DJH0/s800/DSC09447.JPG)
Title: Re: 1973 GMC K2500 Camper Special
Post by: zieg85 on October 29, 2011, 01:56:14 pm
Great looking ride, love the stock stance, hubcaps.  The newer style front bumper doesn't look to bad either.  What is it that is sticking out used for?
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jason S on October 29, 2011, 01:58:49 pm
Photos under the hood with propane.  The engine is filthy right now, but she ran fine all summer with 115 degrees outside temps while blowing cold air in the cab.

The first photo is looking at the passenger side of the engine compartment showing the Impco Model gas regulator with an electric fuel lock-off valve. There is a vacuum operated lock-off that could be used in lieu of the electric lock-off.  The lock-off is simply a valve that is normally closed unless electricity (or vacuum) is applied. So if I have the switch in the cab flipped to gasoline, it will open the lock-off on the gasoline line to the carburetor and the propane lock-off will remain closed (and vice-versa). 
(https://lh4.googleusercontent.com/-Obj5BF_6PNw/TrGlnNrWBvI/AAAAAAAAAA4/2ztOr6ng_iA/s800/DSC00608.JPG)

The second photo shows the Impco 300 propane carburetor, air cleaner and adapter sitting on top of the Quadrajet carburetor.  When operating on propane, there is a cable actuated air valve that closes off air from passing through straight to the gasoline carb. When in propane mode the engine vacuum passes through the propane carb and pulls the propane gas from the regulator  (through the black tube) to the propane carb where it is mixed with air, which then passes through the Q-jet into the intake manifold. 
(https://lh6.googleusercontent.com/-wa0FrZspgaM/TrGllPb4dVI/AAAAAAAAAA0/2klfGUWNtAI/s800/DSC00609.JPG)

The third photo pretty much shows the whole underhood propane setup, with the regulator on the passenger inner fender and the mixer/carb on top of the Q-jet.
(https://lh5.googleusercontent.com/-RiS2_qM_-dU/TrGliuXlpKI/AAAAAAAAAAw/qRC3lflqRx8/s800/DSC00610.JPG)

The fourth photo is a closeup of the Impco Model E propane regulator. The Model E is supposed to be cable of supplying a sufficient amount propane gas at least a 454 cid engine. Smaller displacement engines (like most 6 cylinders) would use a smaller regulator.
(https://lh6.googleusercontent.com/-52rLmVrKJRU/TrGlf90lTEI/AAAAAAAAAAs/Uo0AnFkwgns/s800/DSC00612.JPG)
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jason S on October 29, 2011, 02:14:56 pm
Thanks Zieg. 

It's sitting on an older Rancho 4" lift, I think it's just about the right height for me.

The bumpers, front and rear, are CUCV.  The black pieces sticking out are where the clevis' attach.  I have a Pierce 9,000 lb worm drive winch that I mounted in a special cradle that will bolt up to the front clevis attachments and lower frame.  I'll probably wind up building a dedicated winch bumper sometime, but right now I can remove/install the 250 lb behemoth if I want. 

Here are some photos of the dash cluster and the Spicer lockouts.

(https://lh5.googleusercontent.com/-ukBspvHAlUk/TrGlb1oMTiI/AAAAAAAAAAk/EJskoK08DY0/s800/DSC00614.JPG)
(https://lh6.googleusercontent.com/-rP25fEikjGA/TrGlZtIqaAI/AAAAAAAAAAg/ouzDuxA6bJc/s800/DSC00615.JPG)
(https://lh5.googleusercontent.com/-7BKiXIl74r8/TrGldVPKDaI/AAAAAAAAAAo/1ElNq-TNyHg/s800/DSC00613.JPG)

The NP203 has a part time conversion and had some Warn lockouts when I bought it way back when. I had wanted Spicer hubs for a long time. About 10 years ago I called Spicer and ordered their current hubs, Powertrain, but they were essentially the same as the Warn hubs.  I found a decent set of Spicer Hub-Lok external lockouts about 6 years ago and swapped them for the later style.
(https://lh6.googleusercontent.com/-JmtXUoasRGg/TrHLHsfat5I/AAAAAAAAADs/vTvF8-SQuQU/s800/DSC00617.JPG)
Title: Re: 1973 GMC K2500 Camper Special
Post by: zieg85 on October 29, 2011, 03:52:56 pm
Nice stock touches, tach, stock radio...very nice.  I had those type of hubs on my 72 K20, never had any problems with them.
Title: Re: 1973 GMC K2500 Camper Special
Post by: thirsty on October 29, 2011, 04:32:18 pm
(http://www.suitorsgarage.com/jsuitor/thumbsup.jpg)
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jason S on November 02, 2011, 06:11:26 pm
Thanks Zieg and Oilzum.

 As far as the Spicer hubs go, I guess I'm going to have a post about them.  I'm looking for some parts, specifically O-rings, that may or may not still be available.
Title: Re: 1973 GMC K2500 Camper Special
Post by: VileZambonie on November 02, 2011, 06:15:07 pm
(http://www.suitorsgarage.com/jsuitor/thumbsup.jpg)

This
Title: Re: 1973 GMC K2500 Camper Special
Post by: bake74 on November 03, 2011, 06:19:48 am
     That really is a nice looking truck.  Don't worry, only a select few will know that the bed is of a later model from the gas caps.
Title: Re: 1973 GMC K2500 Camper Special
Post by: Engineer on November 04, 2011, 09:59:43 pm
I approve. :)
Title: Re: 1973 GMC K2500 Camper Special
Post by: JohnnyCanuck on November 09, 2011, 09:48:15 pm
Nice, how much is propane down there?
Title: 1973 GMC K2500 Camper Special
Post by: Macj1983 on November 09, 2011, 10:45:22 pm
What's the draw of going to propane? Versatility ? In a newbie to most of this stuff
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jason S on November 10, 2011, 08:10:45 pm
Thank you, Vile, Bake, Engineer & JohnnyCanuck.

Currently propane is $2.65/gallon as a motor fuel with alternative fuel tax decal. In Oklahoma, if using an alternative fuel (other than gasoline) you are required to pay road taxes or purchase a tax decal yearly (that goes in the lower right of the windshield).  Yes, I drive an alternative fueled vehicle.

I like the propane because my engine has to have at least 89 octane ($3.35/gallon now).  I can drive the '73 GMC to work and pay a little less in fuel than I would to drive my 2005 Chevy and save the miles on the newer truck.

In my experience thus far, propane on an older truck:  it is essentially a "poor man" fuel injection when it comes to start up. I will get it fire up by the third crank in the morning (summer or fall) and then can literally drive away; oil is golden colored at oil change; it's about 115 octane so you'll never have pinging;  it burns very clean; no flooding; never a bad batch of fuel and so on.

The downside:  It has about 85% of the energy content of gasoline, so not as much getup and go; I have to go to a propane supplier to buy fuel; I gave up about 2' of bed for my tank; there is a certain amount of oil in propane and that oil will accumulate in the regulator and propane carb, requiring cleaning; and a few other drawbacks.

This truck is dual fuel right now and the ignition is set for gasoline (timing and plug gaps).  Compression on the 350 is about 9.1: 1, the compression ratio could be increased if this was a dedicated propane truck. However, at present I can run gasoline or propane.  Plus, with the setup I have, I figure that if both 20 gasoline tanks were full and the 100 gallon propane tank was full (i.e., about 80 gallons) , then I could drive over 1000 miles without having to fuel up...
Title: Re: 1973 GMC K2500 Camper Special
Post by: bake74 on November 11, 2011, 12:15:10 am
     1000 miles without fueling up, now that is a road trip.
Title: 1973 GMC K2500 Camper Special
Post by: Macj1983 on November 11, 2011, 07:36:25 am
Wow that's nice a lot of perks there to. Thanks for the info.
Title: Re: 1973 GMC K2500 Camper Special
Post by: beastie_3 on November 22, 2011, 07:55:17 pm
3.35 for 89? lucky...I pay 3.65 for 87!
Title: Re: 1973 GMC K2500 Camper Special
Post by: rmauto1 on May 13, 2013, 08:26:30 am
Wow! What a nice looking truck! What size tires do you have on it?
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jason S on May 15, 2013, 07:08:19 pm
Thank you rmauto1.

The tires are Republic Trail Mark 235/85/R16. 
Title: Re: 1973 GMC K2500 Camper Special
Post by: y5mgisi on November 06, 2013, 01:28:28 am
Adding this to my subscribed threads! Love LOVE the look of this truck!
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jason S on November 06, 2013, 07:25:32 pm
Thanks for the comment y5mgisi... 

Title: Re: 1973 GMC K2500 Camper Special
Post by: Johnny walnuts on November 06, 2013, 09:43:14 pm
Love the factory tach.  Did it come with it from the factory or did you add it?   I have been looking for one for 84 for almost a year now.  I know you can buy them aftermarket, but I would like to find an original from the junkyard or somewhere.
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jason S on November 06, 2013, 10:15:35 pm
Thank you Johnny walnuts...I added the tach about 15 years ago.

There are quite a few posts about factory tachs on this site.  There are still tachometer clusters floating about (ebay, swap meets, websites, etc.), a lot of what you'll find are clusters from medium duty trucks.  If you find a cluster, just be sure to know what you're looking for.
Title: Re: 1973 GMC K2500 Camper Special
Post by: Boonie on November 23, 2013, 11:43:30 am
Im really liking how the wheels and tires look on there.  can I ask what size the wheels are?  and what backspace?
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jason S on November 23, 2013, 07:53:51 pm
The wheels are 7.00" or 7.50" (can't recall which) x 16"  8-lug stock wheels off a '93 Dodge D-250 (3/4-ton) pickup.  They were good and straight; so I cleaned, sanded and painted them.  Stock GMC hubcaps fit without any issues. 

I don't know the backspace, but most of the factory, plain steel 8-lug wheels had similar backspacing between brands.  Just guessing, but I think the mounting area is probably centered on the wheel.
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jmac02 on December 07, 2013, 09:24:02 pm
Nice truck. I love how these look when there still pretty much stock looking.
Title: Re: 1973 GMC K2500 Camper Special
Post by: Engineer on December 08, 2013, 08:17:59 am
I don't know if it is a trend or just coincidence, but I have 2 factory tach clusters. One from a '77, the other from a '78.

The '77 is a mechanical oil pressure gauge, the '78 has an electric oil pressure gauge.

What is odd is that both are from original K-30 factory 4x4 SRW 1-ton trucks. Both trucks being K-30s makes them rare in their own right. I don't know if the factory tach was common on the K-30, or just coincidence that the two that I had came with them......
Title: Re: 1973 GMC K2500 Camper Special
Post by: Captkaos on December 08, 2013, 11:42:34 am
Probably a coincidence, but they are much more common on the 3/4 and 1 tons, but most 1T's  don't have the redline at 5000 like the 1/2T (4000 rpm on some 1Ts)
Title: Re: 1973 GMC K2500 Camper Special
Post by: swissarmychainsaw on October 10, 2014, 09:34:57 pm
Great Looking Truck!

4" lift, what tires are you running on it?  I think that stance is perfect for this vintage 4x4.
Looking to do this on my burb, but it's a 1/2ton!
Title: Re: 1973 GMC K2500 Camper Special
Post by: Jason S on October 11, 2014, 12:22:55 pm
Great Looking Truck!

4" lift, what tires are you running on it?  I think that stance is perfect for this vintage 4x4.
Looking to do this on my burb, but it's a 1/2ton!

Thank you.

The tires are Republic (by Goodyear) - Trail Mark, M/S Radial.  The size is 235-85-R16.

I bought them around in '03 or '04.  There's not a tremendous amount of miles on them, but they've worn very well. After all this time, they don't show any cracking or other abnormal issues.