Purchased a 1969 C10 Short Bed - Pleasanton, CA

[67carry-all]

RE: gas fumes in the garage. Seems like there may be a few potential sources for this, especially the leak at the carb. However, I'd also suggest replacing that gas cap. My truck that otherwise appeared leak-free had a cracked gas cap gasket and filled the garage with fumes. Replacing with a new cap took care of the issue. Make sure it's a "year-appropriate" cap, meaning it's a vented vs. a non-vented cap. Classic Heartbeat, a forum vendor, supplied a nice locking cap.

[Luke87gt]

Originally Posted by 67carry-all

RE: gas fumes in the garage. Seems like there may be a few potential sources for this, especially the leak at the carb. However, I'd also suggest replacing that gas cap. My truck that otherwise appeared leak-free had a cracked gas cap gasket and filled the garage with fumes. Replacing with a new cap took care of the issue. Make sure it's a "year-appropriate" cap, meaning it's a vented vs. a non-vented cap. Classic Heartbeat, a forum vendor, supplied a nice locking cap.

Thank you, I did replace the gas cap gasket (but kept original cap) which resulted in a much tighter fit. The original gasket was badly cracked all around the perimeter.

I need to get that old carb pulled off and addressed along replacement of the rubber fuel lines. Those are really old and soft.

[Bruce F]

Nice truck

The engine could be a 230. I have a 69 Short Step low option (ex US government truck) and thought it was a 250 until the machine shop found out it wasn't at rebuild time.

Bruce

[68bowtie]

The original engine in that truck was a 250.

Page 8 of this pdf for a CS vin.

https://www.gm.com/content/dam/compa...olet-Truck.pdf

[Steeveedee]

Originally Posted by 68bowtie

The original engine in that truck was a 250.

Page 8 of this pdf for a CS vin.

https://www.gm.com/content/dam/compa...olet-Truck.pdf

Good to know, thanks! Makes me wonder about BruceF's SPID.

[Luke87gt]

Originally Posted by 68bowtie

The original engine in that truck was a 250.

Page 8 of this pdf for a CS vin.

https://www.gm.com/content/dam/compa...olet-Truck.pdf

Ok thank you, back to 250 😀

[KevinK7]

Like a few others, I just read this whole thread, that truck looks super clean, nice score.
Regarding the fuel smell/system, worth noting (since I ran into this myself) is to check the sending unit pickup 'sock' (filter). This is typically a nylon mesh and over the years can get brittle and 'disintegrate'.
After having my carb rebuilt, I started having major gas issues (leaking into the intake). What I initially thought was a poor rebuild, turned out to be fragments of the pickup sock preventing the float needle from seating.

Best of luck with the truck, I'll be following along

[Luke87gt]

I got the new reflectors installed, they look pretty good.

I did have to get new slightly longer screws as the ones that came on the truck were too short with the new thick foam gasket.

[Luke87gt]

And some of you may have seen in the other thread but I did pick up a little 350 this weekend. It may be a while before I get to around to the swap however.

[Luke87gt]

I received the dash pad (saddle) and replacement lenses today that I’ve started installing (from SummitRacing)

- 2 grill lights (little rectangular ones)
- 4 side markers
- 2 backup lenses
- 2 tailight lenses

The side markers arrived with a thick foam pad resulting in my stock side marker screws being too short, ugh

I’ll have to get some pics.

[68bowtie]

That’s super nice!!

[Luke87gt]

Finally got the full set of 275/60/15 BFG Radial T/A tires to go onto the 15x8 truck rallies.

Should have those on soon!

[Luke87gt]

Tonight I put the kids to sleep, grabbed a beer, and replaced the valve cover gasket on the 250. I also gave the valve cover a degreasing before I bolted it back up.

The rockers look sludgy, let’s see if this 250 will come back to life.

[Luke87gt]

Also, I haven’t had a chance to trace these wires yet but wondering if you guys may know where each is going…

To clarify, there is a wire coming from the battery’s + lead into the pictured bank. Then there’s 3 additional wires coming off of that hot bank. Thanks

By the way, one thing I am not used to at all is how difficult it is to reach the back of the motor on these C10 trucks lol. For example, getting to those back valve cover bolts should qualify me for the next Olympic gymnastics trials

[SRU1436]

Originally Posted by Luke87gt

Also, I haven’t had a chance to trace these wires yet but wondering if you guys may know where each is going…

To clarify, there is a wire coming from the battery’s + lead into the pictured bank. Then there’s 3 additional wires coming off of that hot bank. Thanks

By the way, one thing I am not used to at all is how difficult it is to reach the back of the motor on these C10 trucks lol. For example, getting to those back valve cover bolts should qualify me for the next Olympic gymnastics trials

Attached is the wiring diagram for the truck. You’re talking about the junction block. I am not sure if the straight 6 has an additional wire. This will help you get started. If you trace them it will help you figure where they go.

The engine bays on these trucks are large, sometimes I use a small step ladder to reach the back.

[Rust_never_sleeps]

Originally Posted by Luke87gt

By the way, one thing I am not used to at all is how difficult it is to reach the back of the motor on these C10 trucks lol. For example, getting to those back valve cover bolts should qualify me for the next Olympic gymnastics trials

I'm 6'5" and I have to use a stool to comfortably doink around with the alternator etc. back there for more than a few minutes
Of course, then I bang my head on the hood a lot
The truck always wins

[Luke87gt]

Thank you for that!

It looks like one of the wires runs to the fuse box. The other is labeled “Engine Ham” … what is that?

And then I need to trace the 3rd mystery wire on my 6cyl

[MikeB]

It's quite common to see other stuff wired to the junction block. But from the factory the junction block has a 12 gauge wire coming from the battery, and a second wire going through a 16 gauge fusible link, and then on to the "splice" on the drivers side of the radiator support. At the soldered splice, the battery wire is connected to the alternator output wire and the fuse panel feed wire.

It's been a while, but the mechanical regulator may also be connected to the splice.

If your truck has an ammeter instead of a warning lamp, the wire that runs from the battery junction block to the splice will actually be a resistance wire with tiny fuses on each end. The ammeter is actually just a voltmeter with "zero" in the center, and it responds to current flow and direction (charge/discharge) across the resistance wire. Kind of a strange way to do it, but I guess GM didn't want to run 30-40 amps into the cabin and use an actual ammeter.

[Steeveedee]

^ GM was smart to use a shunt, in my book. I've been under the dash of many a Mopar with scorched wires at the ammeter. Thermal expansion and contraction eventually created a weak connection.

[fourspeedwagon]

Originally Posted by Luke87gt

Thank you for that!

It looks like one of the wires runs to the fuse box. The other is labeled “Engine Ham” … what is that?

And then I need to trace the 3rd mystery wire on my 6cyl

My guess is that says “Engine Harn.” short for harness. Not sure on the reason for such frugal use of ink there

[MikeB]

Speaking of resistance wire: On some GM cars, instead of a ballast resistor on the firewall, the wire from ignition switch to coil is a resistance wire, and it was bundled in with other wires under the dash.

I worked on a 64 GTO that was hard to start, and wouldn't rev like it should. Turns out someone had added an HEI but left the resistance wire in place, so the distributor was getting only around 9 volts. That resistance wire was melted into an under-dash wire bundle, so I replaced it with a 12ga wire. After that, the engine started easy and revved well. But I had aches and pains from lying on my back!

[Luke87gt]

Well it’s been a motivated weekend. I managed to get the 275/60/15 BFGs onto the 15x8 4.0” BS truck rally wheels.

Not on the truck yet but looks to be a big improvement over the wheels the truck arrived with.

[1970cstblazer]

Still has at least one original T3 headlamp bulb!

[Luke87gt]

Originally Posted by 1970cstblazer

Still has at least one original T3 headlamp bulb!

Wow, how can you tell that 😀

[Luke87gt]

I will say that I am not used to the weight of these truck rally wheels.

I’m not sure what each weighs but it’s by far the heaviest wheel I’ve ever handled on a vehicle lol.

Each wheel needed 2-3oz of weight to balance out. With typical lightweight alloy sedan wheels, I typically need 0-0.5oz to balance.

Tire shop didn’t seem concerned and said although more weight is sometimes needed for steel truck wheels, they balanced out fine in the end.