Rare Vacuum guage
 

I was thinking of installing the fac. vac. guage to cover the only empty spot on the instrumentation. will I have to change the whole dash bezel because of the circuit blue print , or would I be able to just add the guage?

i think you will need a new plastic part that shows all the numbers, and the gauge it self, that i think should do it.

what is this rare vac. gauge?

A vacuum gauge reads manifold pressure [vacuum] expressed as "inches of mercury." For example when your foot is in the throttle, the numbers will be low (5"), but coming downhill in gear, backpressure will build up to read (17" - 20"). The needle on the dial will tell the operator his best economical burn rate when you let off the accelerator a little and the RPMs drop but the speedo stays constant and the vac increases. Also a bouncing needle will tell you if your valves are sticking. And if you got the stereo up real loud and the vac ga. needle drops to zero -- your engine stalled. LOL.
I think some vendors have NOS or re-pop OEM style gauges. They were standard on this vintage 40-50-60 trucks. I would be more apt to trust an aftermarket mfr like AutoMeter to make a good instrument.

Not terribly rare, you will need a inner can, lense and the gauge, the PCB is the same.

These gauges came on the larger trucks for the brake system.

what I meant was that you dont see many factory installs with the stock equipment vacuum setup.I was curious were to get the factory items that are original and if they could work with existing non vac. setups. they are rare in that respect . arent they?

Check in big dump trucks. If you wanted to add a tach and a vac gauge there are kits available for that, not sure if you can get just the vac gauge alone as a kit aftermarket. The vacuum gauge didnt come as an option on 1/2, 3/4 or 1 tons.

I wonder why the empty space is there next to the left of the oil pressure guage?

there is one of these on the burb i just got...i thought you were talking about small gauge that would go in panel behind the clear plastic...and did you say rare? can i get a boatload of money for it??? :D

I would agree that the 5/4 ton and up are the only trucks you can find these in, but I don't think they are standard. I have looked at a few 40-60 trucks, and have yet to see a tach or vac gauge in any of them. I bet it would be listed on the option sticker, but again, I've never seen a truck with one. Just my 2 cents.

this was on your picture page... http://f2.pg.photos.yahoo.com/ph/por...&.dnm=5c00.jpg

That was a pic taken off of this board ;) I have never seen one in "real life." IIRC, that cluster was specially made from an original speed warning cluster with tach and vac added, probably aftermarket conversions.

I dont think that they are aftermarket conversions . I could be wrong but I have seen these listed as rare items several times.I believe that it came as a factory stock item

Like was said previously, they did come in the 40, 50, and 60 series. They never came in the 10, 20, and 30 series. The people that have them in there smaller trucks put them in. I have one in my 1/2 ton, but it taken from a larger truck and put in.
The 'spare' hole is in the 10, 20, and 30 series because GM used the same setup in all of their trucks in those years - 10-60 series, so they put the empty spot in the smaller trucks.
Some of the big trucks also came with an air pressure guage in that spot. Those seem to be hard find as well.

Shawn

So I guess they were "optional" in the 40-50-60 series trucks. The OEM is sort of rare -- no idea of value -- I saw a repop in a vender's catalog for $50 +.
CG your Sun gauge looks like it's seen some miles. An aftermarket gauge maybe cost $10 or $15 from JC Whitney back in the day. I have a Moon Eyes Vac I bought at the local hot rod shop many years ago on the pick-up. Still worked last time the truck was running. I have a new AutoMeter Vac for the Jimmy waiting to be installed. It maybe ran me $30. Once you get used to them, they're neat to have.

It's not going to be "optional" as in " ... and I'll take a vacuum gauge too" when I buy it.

It's going to depend on the type of braking equipment installed in the big truck.
If you have Air Brakes, you are going to get the Air Pressure gauge.
If you have the Vacuum assist braking you will get the vacuum gauge.
If you have the standard, base hydraulic braking, you will probably have no gauge - neither Vacuum nor Air Pressure installed; and just have the blank hole.

I got a gauge set I got off a tandum. I pais $80 for the whole truck.Annywais heres my guage cluster.

If you want to put a factory vacuum gauge in your dash and make it look right, then you will need to change the lens, and the face tin for the gauges. You can drill a hole in the mounting tin for the gauge itself. The dashes that have factory vacuum gauges have the hole in the face tin punched with the edge rolled just like all of the other holes in the tin. To just cut the hole in the tin is easely spotted and doesn't look like the other gauges when lit up also. WES www.ClassicHeartbeat.com