6 cyl tac or V8 tac question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MARIOS68PANEL · 02-19-2012, 10:33 PM

I just got a 67 today. It was an original 6cyl truck.
It has a vac/tac cluster. I dont know if it is original. how can I tell if its a 6cyl tac or V8..Also it has no numbers around the tac. glove box tag says 04253AB Amp meter/oil gauge.any help would be great.

**too much stuff** · 02-19-2012, 10:38 PM

You will have to pull it out and see the back of the tach head for a stamp of "6 cyl" or the part number. Or hook it up and see how it reads.

Vacuum didn't come in 1/2 to one ton trucks and your speedo is a 71-72.
Definately added if not listed.

Duncan and son · 02-19-2012, 11:25 PM

Quote:

Originally Posted by too much stuff

You will have to pull it out and see the back of the tach head for a stamp of "6 cyl" or the part number. Or hook it up and see how it reads.

Vacuum didn't come in 1/2 to one ton trucks and your speedo is a 71-72.
Definately added if not listed.

x2

MARIOS68PANEL · 02-19-2012, 11:35 PM

what is the differance between the speedo`s ? why are there no numbers around the tach? any Ideas ?
And If I go back to cluster with gauges, Whats this cluster worth?

1972RedNeck · 02-19-2012, 11:43 PM

My guess is the tach was added but the "number piece" wasn't changed.

I could have sworn I saw a 1/2 ton on here with a vac gauge listed on the SPID.

**too much stuff** · 02-20-2012, 12:01 AM

Just a matter of changing the lens to a tach lens. Looks to be a decent cluster. Probably worth $250 needing a lens if the back is in decent shape.

Livrat · 02-20-2012, 12:03 AM

Quote:

Originally Posted by MARIOS68PANEL

what is the differance between the speedo`s ? why are there no numbers around the tach? any Ideas ?
And If I go back to cluster with gauges, Whats this cluster worth?

The 71/72 speedos have a round hi beam indicator light where as the 67-70 ones were rectangular, the tach cluster looks odd because you have a non-tach lense

MARIOS68PANEL · 02-20-2012, 12:14 AM

another thing is it has an idiot light that says (Tandom Lock) on the fuel gauge side. never heard of that myself.
I have turned this into two threads.

burb71 · 02-21-2012, 05:17 AM

Tandom lock is for the med duty trucks, C/40, 50 & 60

No numbers on tach lens, lens is from a non tach dash

seetheusa · 02-26-2012, 04:32 PM

I'm new so if I'm do'n something wrong I'm sure you'll let me know. the dash may be out of the big trucks c50 whatever the 6 tach in the one i got is cable drive like the speedo(and big block vettes)startes overreving at 3500 and that looks like air gauge not a vac.big tipoff.and yes some tight ass didn't spring for the correct lens.release the hounds!

seetheusa · 02-26-2012, 04:41 PM

ok at second look that could be a vac and on my tach the yellow to red colors for over rev are painted on the face of tach.as far as the cable drive on mine could be how they did it in 67.goodluck

**70shortfleet** · 02-26-2012, 05:34 PM

The cable driven tachs for these truck are for diesel engine trucks and lens only go to 4000 rpms

**too much stuff** · 02-26-2012, 06:02 PM

Quote:

Originally Posted by 70shortfleet

The cable driven tachs for these truck are for diesel engine trucks and lens only go to 4000 rpms

This is correct. From the front, you can not tell a 6cyl from an 8. Actually, if the numbers are gone on back, you can't tell that way either by looking.

02-19-2012, 10:33 PM	#1
MARIOS68PANEL Active Member Join Date: Mar 2005 Location: North Highlands. California Posts: 449	6 cyl tac or V8 tac question I just got a 67 today. It was an original 6cyl truck. It has a vac/tac cluster. I dont know if it is original. how can I tell if its a 6cyl tac or V8..Also it has no numbers around the tac. glove box tag says 04253AB Amp meter/oil gauge.any help would be great. Attached Images __________________ 67 short step 71 Custom

02-19-2012, 10:38 PM	#2
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,801	Re: 6 cyl tac or V8 tac question You will have to pull it out and see the back of the tach head for a stamp of "6 cyl" or the part number. Or hook it up and see how it reads. Vacuum didn't come in 1/2 to one ton trucks and your speedo is a 71-72. Definately added if not listed. __________________ 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

02-19-2012, 11:35 PM	#4
MARIOS68PANEL Active Member Join Date: Mar 2005 Location: North Highlands. California Posts: 449	Re: 6 cyl tac or V8 tac question what is the differance between the speedo`s ? why are there no numbers around the tach? any Ideas ? And If I go back to cluster with gauges, Whats this cluster worth? __________________ 67 short step 71 Custom

02-20-2012, 12:01 AM	#6
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,801	Re: 6 cyl tac or V8 tac question Just a matter of changing the lens to a tach lens. Looks to be a decent cluster. Probably worth $250 needing a lens if the back is in decent shape. __________________ 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

02-20-2012, 12:14 AM	#8
MARIOS68PANEL Active Member Join Date: Mar 2005 Location: North Highlands. California Posts: 449	Re: 6 cyl tac or V8 tac question another thing is it has an idiot light that says (Tandom Lock) on the fuel gauge side. never heard of that myself. I have turned this into two threads. __________________ 67 short step 71 Custom Last edited by MARIOS68PANEL; 02-20-2012 at 12:21 AM.

02-21-2012, 05:17 AM	#9
burb71 Active Member Join Date: Oct 2002 Location: Ft. Myers, Fl Posts: 1,716	Re: 6 cyl tac or V8 tac question Tandom lock is for the med duty trucks, C/40, 50 & 60 No numbers on tach lens, lens is from a non tach dash

02-26-2012, 04:32 PM	#10
seetheusa Registered User Join Date: Mar 2008 Location: indianapolis indiana Posts: 3	Re: 6 cyl tac or V8 tac question I'm new so if I'm do'n something wrong I'm sure you'll let me know. the dash may be out of the big trucks c50 whatever the 6 tach in the one i got is cable drive like the speedo(and big block vettes)startes overreving at 3500 and that looks like air gauge not a vac.big tipoff.and yes some tight ass didn't spring for the correct lens.release the hounds!

02-26-2012, 04:41 PM	#11
seetheusa Registered User Join Date: Mar 2008 Location: indianapolis indiana Posts: 3	Re: 6 cyl tac or V8 tac question ok at second look that could be a vac and on my tach the yellow to red colors for over rev are painted on the face of tach.as far as the cable drive on mine could be how they did it in 67.goodluck

02-26-2012, 05:34 PM	#12
70shortfleet Senior Member Join Date: Apr 2010 Location: St.Peters, MO Posts: 2,242	Re: 6 cyl tac or V8 tac question The cable driven tachs for these truck are for diesel engine trucks and lens only go to 4000 rpms



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