stock in dash tach question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

JPPA1972 · 06-30-2007, 09:43 PM

Hi Everyone,

I am new to the site and have been reading some of the posts the past few days before I decided to finally ask a question.

I got a 1972 3/4t 250 3sp MT C20, fleetside long bed that my buddy found for me by chance. My first car was a 1972 C10 350 4X4. which I loved, but I was young and never had the money to fix it up. All these year I have always wanted to get a 72 and restore it, well last week my dream came true.

My question is, this truck has the stock 250 6cyl in it, I don't plan on changing the motor at this time, can you hook up a stock gauge cluster dash with the tach, for some reason I thought I read that it is only available in the V8 models. Thanks.

**Ironhorse** · 06-30-2007, 09:53 PM

Welcome to the best truck board on the 'net. Yes, you can install the tach dash in your truck but to be original it needs to be the 6 cyl. style tach. It reads only to the 4,000 rpm. range and not 5,000 rpm. like the 8 cyl. tach. I have seen pics of them so I know they exist but have not seen one in real life. Even the 8 cyl. tachs don't seem really plentiful and at swap meets do pull some pretty decent $$$. $250-$275 in un-restored dash cluster seems to be what I have found. I found my 8 cyl. tach at a local yard nearly 15 years ago for $15 I pull and held on to it until I could re-store my '71 4x4. Good luck with your project and Keep On Truckin'

**too much stuff** · 07-01-2007, 10:35 AM

Actually, the 6 cyl tach reads to 5,000 rpms also and look identical to the v-8 tach. There should be a stamp on the back to designate 8 cyl or 6 cyl. I have heard you can calibrate a tach head by adjusting the small screw from the back. I have never tried this however. The 4,000 rpm would be a diesel tach with a mechanical drive.
Welcome...

Longhorn Man · 07-01-2007, 11:15 AM

your best bet in locating one would be in the bigger trucks, c/40 and up, but it'll still be a hard find. FYI, you can't use the inst panel bezel from the big truck, but your c/10 - c/30 one will bolt right on.
There were stoclk tachs avalible on all engines in these trucks, inline six, v 8, diesels, and V6 engines too.

OhNoJoe · 07-01-2007, 11:40 AM

Not to hy jack the tread.. but I'm in the same boat with my 292 I'm rebuilding. I would like to put a tach in but every thing I see is for a v8. Is there a different wiring harness or something?
THanks,
Joe

OhNoJoe · 07-15-2007, 12:20 PM

no one??

Bob Moore · 07-15-2007, 12:50 PM

Joe - this just a guess but I would think the difference is in the tach head registering 6 pulses vs 8 pulses. I think the wire harness would be the same(still just a guess though).

67stepside · 07-15-2007, 01:15 PM

My tach is a used one and it registers way to low. Is there an adjustment on them to calibrate them?

byrd · 07-15-2007, 01:24 PM

Quote:

Originally Posted by 67stepside

My tach is a used one and it registers way to low. Is there an adjustment on them to calibrate them?

Yep a screw in the back of the fact tach is used to calibrated them, ther may be a little piece of paper covering the hole...Randy

06-30-2007, 09:43 PM	#1
JPPA1972 Registered User Join Date: Jun 2007 Location: Oxford, New York Posts: 9	stock in dash tach question Hi Everyone, I am new to the site and have been reading some of the posts the past few days before I decided to finally ask a question. I got a 1972 3/4t 250 3sp MT C20, fleetside long bed that my buddy found for me by chance. My first car was a 1972 C10 350 4X4. which I loved, but I was young and never had the money to fix it up. All these year I have always wanted to get a 72 and restore it, well last week my dream came true. My question is, this truck has the stock 250 6cyl in it, I don't plan on changing the motor at this time, can you hook up a stock gauge cluster dash with the tach, for some reason I thought I read that it is only available in the V8 models. Thanks.

06-30-2007, 09:53 PM	#2
Ironhorse Senior Member Join Date: Jul 2001 Location: Wellington, Ks Posts: 10,294	Re: stock in dash tach question Welcome to the best truck board on the 'net. Yes, you can install the tach dash in your truck but to be original it needs to be the 6 cyl. style tach. It reads only to the 4,000 rpm. range and not 5,000 rpm. like the 8 cyl. tach. I have seen pics of them so I know they exist but have not seen one in real life. Even the 8 cyl. tachs don't seem really plentiful and at swap meets do pull some pretty decent $$$. $250-$275 in un-restored dash cluster seems to be what I have found. I found my 8 cyl. tach at a local yard nearly 15 years ago for $15 I pull and held on to it until I could re-store my '71 4x4. Good luck with your project and Keep On Truckin' __________________ 1971 Chevy 1/2T 4x4 LWB 350 V-8 Was sm465-now 350TH/np205 Tilt, Tach, Towhooks Original Truck AM/FM Wellington, Ks

07-01-2007, 10:35 AM	#3
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,787	Re: stock in dash tach question Actually, the 6 cyl tach reads to 5,000 rpms also and look identical to the v-8 tach. There should be a stamp on the back to designate 8 cyl or 6 cyl. I have heard you can calibrate a tach head by adjusting the small screw from the back. I have never tried this however. The 4,000 rpm would be a diesel tach with a mechanical drive. Welcome... __________________ 67 gmc custom lwb dakota truck. Sold...And bought back 69 swb 4x4 project (in progress) 70 c-10 lwb texas truck 70 4x4/BB/bkts/posi/tach(retired) 70 swb (wifes) 70 jimmy camper 71 K-5 factory 2wd 71 cheyenne 4x4/tach/posi/ plow rig 71 Cheyenne20 BB, buckets, tach, tilt, 4 speed 72 jimmy CST wyoming rig 72 jimmy Colorado rig 72 lifted texas 4x4 3/4 ton burb 65 fury conv. 383/auto 65 chrysler 300 "L" 413 auto

07-01-2007, 11:15 AM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: stock in dash tach question your best bet in locating one would be in the bigger trucks, c/40 and up, but it'll still be a hard find. FYI, you can't use the inst panel bezel from the big truck, but your c/10 - c/30 one will bolt right on. There were stoclk tachs avalible on all engines in these trucks, inline six, v 8, diesels, and V6 engines too.

07-01-2007, 11:40 AM	#5
OhNoJoe Registered User Join Date: May 2006 Location: Springfield Illinois Posts: 182	Re: stock in dash tach question Not to hy jack the tread.. but I'm in the same boat with my 292 I'm rebuilding. I would like to put a tach in but every thing I see is for a v8. Is there a different wiring harness or something? THanks, Joe

07-15-2007, 12:20 PM	#6
OhNoJoe Registered User Join Date: May 2006 Location: Springfield Illinois Posts: 182	Re: stock in dash tach question no one??

07-15-2007, 12:50 PM	#7
Bob Moore Registered User Join Date: Feb 2004 Location: Tacoma WA Posts: 1,365	Re: stock in dash tach question Joe - this just a guess but I would think the difference is in the tach head registering 6 pulses vs 8 pulses. I think the wire harness would be the same(still just a guess though). __________________ 67 C-20 LWB, tilt, speed alert, vac, 454, T400 67 C-10 SWB, factory air with more to follow

07-15-2007, 01:15 PM	#8
67stepside Registered User Join Date: Jan 2002 Location: Columbus, IN. USA Posts: 140	Re: stock in dash tach question My tach is a used one and it registers way to low. Is there an adjustment on them to calibrate them?

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