Re: Restoring Rusty
 

You asked about cylinders, so I pointed out those numbers are not the total number of cylinders they are 2 stroke or 2 cycle and 4 stroke or 4 cycle there is no 8 cycle engine that I know of

Re: Restoring Rusty
 

Working on an 80 K5 back around 1998, I discovered the need for the offset extension to get the oil pressure sending unit to fit into the tight space.

Someone else must have become frustrated and installed the idiot light sending unit. I simply wanted the gauge to work so I bought what the local auto parts store said I needed...the big sending unit. After I could not get it to fit under the distributor I came up with the idea of using the elbow extension. It worked. I had no idea that's what was required. Again, I just wanted it to work.

I had forgotten about that until now. I'll have use that info once I start but this old 79 back together. I too will be going from idiot lights to gauges.

Re: Restoring Rusty
 

Pink is ignition power. You need add one more for the 78 cluster.
Tan should be the fuel sender. GM wired the harness for both large and small fuel gauge. You'll have to change terminal positions for the 78 cluster.

Re: Restoring Rusty
 

1974 used a sheet metal ground for the main cluster ground wire. Sounds like the cluster Ground splice gave up the ghost.

Re: Restoring Rusty
 

Good lord you been busy.....good grief.

Re: Restoring Rusty
 

Are you sure that's a v8 tach and not for a 6?

Re: Restoring Rusty
 

If it were a 6cylinder tach it would read too high.

Freq_Hz=(RPM/60)*(CYL*0.5)

An 8cylilnder at 1500 RPM is generating a 100HZ signal
A 6cylinder at 2000 RPM is generating a 100HZ signal
A 4cylinder at 3000 RPM is generating a 100HZ signal

Re: Restoring Rusty
 

If the tach gets pulses inductively from the #1 cylinder, then it doesn't matter how many cylinders the engine has. #1 only fires once for every two revs.

If you can drive at a known speed (like using a GPS), and we know your tire size and rear gears, we can figure out what RPM the engine is actually turning.

Re: Restoring Rusty
 

Yup. But the GM tach is reading the ignition impulse frequency from the coil and it's lower than the very accurate inductive pickup tach.

What I was explaining was why I know the GM tach is not a 6 cylinder unit... The needle would point to @2000 RPM on a 6cyl tach. @500 RPM too high at @1500 (1490) RPM on the inductive tach. :D
It's a calibration problem with the analog GM tach drive circuit and it can be repaired.

Re: Restoring Rusty
 

Shoot, I was talking about the Mac timing gun reading, not the GM tach.

Another reason you're right that it's not a six cylinder tach is that, all the six cyl trucks I've seen, including mine, are pretty basic, and are unlikely to have the full gauge package.

Re: Restoring Rusty - Oil Pressure Sending Unit Wire
 

OK fellas I was able to make it to the junk yards this morning to take advantage of the 50% off sale, although I did not find a radiator core support I did score some little things that I needed, some that are hard to find, so allow me to share

first off of a 1979 I pulled the Oil Pressure Sender Unit wire, that's right I could have made my own, but by pulling an original I get the right plug, the right color, and I get to see where it plugs into the bulk head connector

if you just take your time with some needle nose pliars you can actually push out one of them GM connectors, like so...

Re: Restoring Rusty
 

still staying with the '79 I decided to see if I can find a similar black ground wire like the loose one in my truck and see where it bolts up to

I found a similar wire so I unscrewed the loop end and cut the other end where it splices into the wiring harness so I can graft it in properly to my own, score

Re: Restoring Rusty
 

then I moved on to a 76 manual 4 speed like mine, the first manual I ever saw

this is where I found the Holly Grail... a part I have been looking for, for almost a year and knew the aftermarket one I bought wasn't even close to the original, I also got an answer to where these little two hole round brackets go and en explanation how this super tough spring can span such a huge distance

I give you the clutch pedal spring at last...

Re: Restoring Rusty - Clutch Pedal Spring
 

here is my old broken spring with one mystery bracket, the used replacement one with both brackets which I paid $2.50 for, and the silly thing I bought somewhere online claiming to be the proper new replacement, shame on them

Re: Restoring Rusty - Headlight Switch Knob
 

also from the '76 picked up the Headlight Switch knob and rod for $1.50, LMC Truck wants $14.00 bucks for it and I doubt it would match my black knobs, score

my old one gave up the ghost, the insides crumble and it just slides right off

I like these small victories! How about you?

Re: Restoring Rusty - Junction Block & Positive Battery Cable
 

then I visited this '73 where I thought I could score the radiator core support, it looked all shinny and black, I was guessing the truck was recently repaired in the front, but... only to remove every bolt but one, you guessed it the rusty one under the battery tray in the bottom lowest corner, that's when I realized that although all the metal is there, the lip in the corner is paper thin, the rust has already gotten to it, so I passed on it, although unscrewing all those 50 screws was hecka fun

I did walk away with this junction block, but Greg we didn't realize you needed one? Well I sorta drove the truck to work with the wiring harness loosened up from the firewall and I smelled plastic burning on the way home, and then I found out it was my old junction block melting on the ol' exhaust manifold

I also picked up a proper Positive Battery Cable ($2.50) with a RED terminal, I wich the entire cable was red, but I will settle for at least a red tip, that way if the wifey has to jump start me one day she won't cross the jumper cables

Re: Restoring Rusty
 

Re: Restoring Rusty
 

Awh, sh1t, I didn't know you were looking for that clutch spring. I'm nearly certain I have one in my parts bin I could have shipped you.

I notice your battery cable is for a side terminal battery. I know GM used the side terminals a lot, but in my opinion, they're crap compared to a top terminal. When the corrosion starts on the side terminal, it's hidden by the wire and you're not aware of it. Not so with the top terminal, and the connection surface area seems larger too.

Re: Restoring Rusty
 

Agreed on the terminals. I much prefer top post with marine clamps and then make my own 4g wiring.

Re: Restoring Rusty
 

My friend I hate those things with a passion, they get stripped, they are terrible for jumper cables, I hate them more than you. I may be thinking of a conversion to top terminals at some point, but I just bought that battery brand new and it don't have both and top terminals just the lame side ones.

Re: Restoring Rusty
 

Bummer. I was thinking your new battery was side terminal only.

Re: Restoring Rusty
 

considerin' these ugly spark plug wire booties for my too close to the headers problem, saw this pic on Craigslist today - please don't let me do it, they are ugly as heck

Re: Restoring Rusty
 

They may be ugly but they work. I run a set on my 454. Only need them for 2 wires but it looks dumb unless it's a complete set on the engine. Also they look a bit better if they are not that tan color. I went with black ones.

Re: Restoring Rusty
 

Thanks for the pics Gregski, very clean install BTW

Re: Restoring Rusty
 

You sure did a good job, I wouldn't begin to know how to do all that! Al

Re: Restoring Rusty
 

Congrats on the score. Now find me a core support as well. Good luck. Mines not only rusty but bent as well......

Re: Restoring Rusty
 

I have MSD plug wires and they are withstanding headers really well.

I buy those braided heat thingies individually, take the ring out of them, and use them as a "TIG Finger" for welding.

http://www.weldmarkuk.com/wp-content...ger-in-use.png

Re: Restoring Rusty
 

That 6 disconnect ground buss bar mounted to the E-Brake pedal bracket is 1978-91. 1973-1977 use a ring terminal direct to the sheet metal under the dash. The 78-91 part is nicer to deal with. Nice scores BTW.

Re: Restoring Rusty
 

Yeah I grabbed one of those 6 disconnect ground bars myself but I discovered to use it requires a special type of connector to use with said bar.

Or maybe I just ned to use larger female spade terminals?

Re: Restoring Rusty
 

The 12004267 female Packard 56 singles look pretty but a quality disconnect terminal will work fine.
If you have the 12004267 plastic housing the Packard 56 Female terminals are easy to find.

Re: Restoring Rusty
 

For the battery side terminals, I used two brass side post adapters with the studs on the back, but I used the ones for the double-wire setup, so they are longer on the battery end. I screw it through the cable so it just dead-ends in the battery, to catch all the threads, then tighten a nut down onto the cable. The studs off the back side give me something to connect accessories to, as well as jumper cables. I should have a picture here somewhere.

Here it is. I cut the ring off that held the old clamp bolt captive. The yellow residue is from some 3M weatherstrip adhesive I used to glue a cap on it at one point. But you can see how the clamping bolt is not all the way down, there is a nut clamping the cable.
http://users.rcn.com/weyand/smalls/2...022407crop.jpg

This is the part you want. Note the "LONG" in the description. That is because some GM side post setups had TWO cables on one clamp.
http://optimatrays.com/viewitem.php?type=accessory&id=5

Anyway, this way you engage *all* of the threads in the battery, and won't strip it, and those big hexes are a lot easier to deal with than the small ones.

Re: Restoring Rusty
 

not sure Jeremy but it does have a 4 Wheel Lock light on it (under the speedo) so I'm assuming it came off of a V8 truck since I don't think they had 6 cylinder 4x4s, please correct me if I'm wrong

Re: Restoring Rusty
 

Kinda late to reply to this one, and I believe we settled it that indeed it is ground, but just for foresuredness (lol) and Keith may correct me, I don't recon they had electronized the seat belts back in 1974 as I don't think they even made shoulder belts mandatory yet back then

the new gauge cluster circa 1979 does have a seat belt light under the tachometer

Re: Restoring Rusty
 

Sunday Morning
to the tune by Maroon 5

Sunday morning, truck is calling
Spin some wrenches, scrape some skin
Clouds are shrouding us in moments unforgettable
You twist to fit the part that wont go in
But things just get so crazy, fixing rust gets hard to do
And I would gladly hit the road, get up and go if I could
That someday it would bring me back to you
That someday it would take me back to you
That may be all I need
In darkness, my truck is all I see
Come and test your skills with me
Driving slow on Sunday morning
And I never want to leave
Fingers trace your every outline
Paint your body with my hands
Back and forth we sway like branches in a storm
Change the weather (stripping), hold together where it bends
That may be all I need
In darkness, my truck is all I see
Come and test your skills with me...

Re: Restoring Rusty - 74 & 78 Printed Circuit Boards
 

today we hope to complete the 74 => 78 gauge cluster swap

below for high level comparison I included a picture of the old 74 printed circuit board (top pic) and below it a picture of the old 78 printed circuit board

the idea is to just give you an idear that they is different, we do not expect you to use these fotos to trace and compare the actual circuits

also this is what they look like to Superman ie if you could see through the blue housing this is what they look like facing you the way the gauges face you naturally, I find that when you turn the cluster over and are looking at the back side, things are super confusing because right is left and left is west, you git the idear

Re: Restoring Rusty
 

and so we prepare and prepare for this cluster surgery, just tracing these boards on paper and making these drawings was a great exercise to acclamate to what lies ahead

I present to you the Anti Schematic Wiring Schematics

Pic 1 - 1974 gauge cluster with mechanical oil gauge absent tachometer

Pic 2 - 1978 gauge cluster with electronic oil gauge with tachometer

Re: Restoring Rusty
 

My 74 is a Canadian truck with only lap belts and yes the ground for the harness is to the metal on the dash where the 6 prong bar goes later.

Re: Restoring Rusty
 

Thanks, so in '74 there is no 6 prong bar, that came later? I don't have one so I don't know if I am missing one or it never had it, thanks

Re: Restoring Rusty
 

took my time and removed and labeled every single wire from the gauge cluster connector plug

here they colorphabliclly

Light Green - Hi Beam Light Bulb

Gray - Five Cluster Illumination Lights

Black - Ameter

Black with White Stripe - Ameter

Pink - Positive Switched Ignition Power

Tan with Black Stripe - Brake Light Bulb

Tan - Fuel Gauge

Dark Green - Water Temp Gauge

Black - Ground for Water Temp, Cluster Lights, Fuel Gauge

Dark Blue - Right Turn Signal Light Bulb

Light Blue - Left Turn Signal Light Bulb

Dark Blue - will be Oil Pressure Gauge once installed

Re: Restoring Rusty - Fuse Box
 

now we're playing with Power, no literally we're actually playing with... ah you get the joke

now Greg why in the world did you tear up this fuse box panel thing

two reasons:

1. We had to A. castrate the dangerous Ameter wire(s) and B. graft the new Electric Oil Pressure wire

2. I was curious how all this wiring works and what's behind the fuse box, because starring at wiring diagrams just gives me a headache