quick tach cluster question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chev74 · 12-21-2007, 03:12 PM

Okay, my dad and i have been asking each other this question this evening -

Which tach clusters (what years) fit a '74? The difference, we believe is where the windshield wiper switch is located, correct? I am looking to buy some and need to know the exact ones to look at.

also if there are part numbers, which ones to look for?

P.S. this is my christmas present possibly, so dont tell mhicks

beaterC10 · 12-21-2007, 04:43 PM

Actually the two concerns are the presence of an ammeter or volt meter and mechanical or electrical oil pressure. You are looking for something 77 or earlier I think. Crossy would be the member to ask for detailed information on tachs.

**N2TRUX** · 12-21-2007, 07:16 PM

Lets see if I can remember until Capt Kaos, Crossy or Russell come along to verify.

73-76= Amp or Ammeter, mechanical oil pressure
77= Volt or Voltage gauge, mechanical oil pressure
78+= electric oil pressure

68K20 x Drill · 12-21-2007, 10:06 PM

The speedo shop tells me an HEI will fry the tach from a non HEI truck.
I just paid $260 to get one repaired.

James McClure · 12-21-2007, 11:20 PM

Drill: I would think the speedo shop is incorrect. A tach is a tach. You can take a Sun tach and switch it into anything you want, even a magnito ign and it keeps on ticking, so I would surmise you could also do it with a factory tach. There is a seperate connection on HEI just for a tach. Yours MAY have a white wire in it now thats the one you want to connect to. The top of the connector block at the distributor actually says "tach". Let me know how you do. jim

68K20 x Drill · 12-21-2007, 11:34 PM

Building a '74 truck for a friend awhile back he had a tach that didn't work. I checked all the wiring, and it still didn't work. I swapped in a newer motor with HEI, and it still didn't work (it did get warm if plugged in). Well, we though it would be cool to have the factory gauge, So we took it to Palo Alto Speedometer. It took them an hour or so to put a new board in the back, and it works great now.
They said sometimes the old points ones die if you hook up the HEI. I am somewhat skeptical myself, but with the repair running $250-300, I'll be cautious .

Prong · 12-25-2007, 11:57 AM

You want a 73-75 cluster. The telltale indicator is that it will have an AMP gauge.

tbirdman88 · 12-25-2007, 02:50 PM

I have a tach cluster from a 73 or 74,I dont know if it works. I had bought it for my 87, cant use it because of the speedometer,needs to have a speed buffer for the trans.
I would like to sell it if anyones interested.

send me a private message with contact info.

87swbcrewcab
donnie

12-21-2007, 03:12 PM	#1
chev74 Addicted to Chevy Join Date: Dec 2004 Location: Tyler, Tx Posts: 857	quick tach cluster question Okay, my dad and i have been asking each other this question this evening - Which tach clusters (what years) fit a '74? The difference, we believe is where the windshield wiper switch is located, correct? I am looking to buy some and need to know the exact ones to look at. also if there are part numbers, which ones to look for? P.S. this is my christmas present possibly, so dont tell mhicks Last edited by chev74; 12-21-2007 at 03:12 PM.

12-21-2007, 04:43 PM	#2
beaterC10 Senior Member Join Date: Jul 2003 Location: Indianapolis, IN Posts: 1,277	Re: quick tach cluster question Actually the two concerns are the presence of an ammeter or volt meter and mechanical or electrical oil pressure. You are looking for something 77 or earlier I think. Crossy would be the member to ask for detailed information on tachs.

12-21-2007, 07:16 PM	#3
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Re: quick tach cluster question Lets see if I can remember until Capt Kaos, Crossy or Russell come along to verify. 73-76= Amp or Ammeter, mechanical oil pressure 77= Volt or Voltage gauge, mechanical oil pressure 78+= electric oil pressure __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

12-21-2007, 10:06 PM	#4
68K20 x Drill Registered User Join Date: Apr 2007 Location: Freedom CA Posts: 488	Re: quick tach cluster question The speedo shop tells me an HEI will fry the tach from a non HEI truck. I just paid $260 to get one repaired. __________________ 68 Chevrolet k20 Longbed 350 SM465/205, Dana 44, 14bolt, Power steering, Power Disk Brakes, 35" BFGs. 84 Chevrolet Suburban K20 6.2 Banks turbo TH400/NP208 Now with G80 68 GMC C20 Parts? Truck And a few cars

12-21-2007, 11:20 PM	#5
James McClure One shot, one kill. Join Date: Dec 2007 Location: Saratoga Springs NY Posts: 859	Re: quick tach cluster question Drill: I would think the speedo shop is incorrect. A tach is a tach. You can take a Sun tach and switch it into anything you want, even a magnito ign and it keeps on ticking, so I would surmise you could also do it with a factory tach. There is a seperate connection on HEI just for a tach. Yours MAY have a white wire in it now thats the one you want to connect to. The top of the connector block at the distributor actually says "tach". Let me know how you do. jim

12-21-2007, 11:34 PM	#6
68K20 x Drill Registered User Join Date: Apr 2007 Location: Freedom CA Posts: 488	Re: quick tach cluster question Building a '74 truck for a friend awhile back he had a tach that didn't work. I checked all the wiring, and it still didn't work. I swapped in a newer motor with HEI, and it still didn't work (it did get warm if plugged in). Well, we though it would be cool to have the factory gauge, So we took it to Palo Alto Speedometer. It took them an hour or so to put a new board in the back, and it works great now. They said sometimes the old points ones die if you hook up the HEI. I am somewhat skeptical myself, but with the repair running $250-300, I'll be cautious . __________________ 68 Chevrolet k20 Longbed 350 SM465/205, Dana 44, 14bolt, Power steering, Power Disk Brakes, 35" BFGs. 84 Chevrolet Suburban K20 6.2 Banks turbo TH400/NP208 Now with G80 68 GMC C20 Parts? Truck And a few cars Last edited by 68K20 x Drill; 12-21-2007 at 11:34 PM.

12-25-2007, 11:57 AM	#7
Prong Registered User Join Date: May 2007 Location: CO Posts: 475	Re: quick tach cluster question You want a 73-75 cluster. The telltale indicator is that it will have an AMP gauge.

12-25-2007, 02:50 PM	#8
tbirdman88 87 short crewcab Join Date: Jan 2004 Location: duncan okla Posts: 82	Re: quick tach cluster question I have a tach cluster from a 73 or 74,I dont know if it works. I had bought it for my 87, cant use it because of the speedometer,needs to have a speed buffer for the trans. I would like to sell it if anyones interested. send me a private message with contact info. 87swbcrewcab donnie



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