Those with factory tachs... check in! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72BlckButy · 02-17-2011, 09:46 PM

I'm looking to see if someone can post a picture of where the tach wire comes through the firewall. I'm trying to determine which dimple is the 'correct' dimple as there are 4 to pick from depending on the options installed.

I "think" it's the 3rd from the bottom, but I want to make sure I'm selecting the correct one. Working on a project for my FIL.

Please post a picture of your firewall.

Thanks in advance guys!
Nate

ETsC10 · 02-17-2011, 10:59 PM

Bump for ya~~ or should I say 'dimple'?

firedog · 02-17-2011, 11:51 PM

Speaking of the fil where are the pixs of his truck?
Posted via Mobile Device

72BlckButy · 02-18-2011, 11:56 AM

bttt...

I have seen this thread, but I want to locate the exact dimple that would have been utilized for the tach wrie.

http://www.67-72chevytrucks.com/vboa...+wire+firewall

Is this the correct dimple???

Name: Tach%20grommet%20hole.jpg
Views: 379
Size: 36.5 KB

Name: Tach%20grommet%20hole.jpg
Views: 379
Size: 36.5 KB

Quote:

Originally Posted by firedog

Speaking of the fil where are the pixs of his truck?
Posted via Mobile Device

More to come.

smorg007 · 02-18-2011, 12:26 PM

My dimple where I drilled my tach hole was exactly where the picture shows it to be. Not quite as deep as those in the picture. I used the dimple as a punch hole for the 3/4 bit. There was even a perforated hole in my firewall material to match this location.

72BlckButy · 02-18-2011, 07:30 PM

Thanks for the post.

What did you mean by 'not quite as deep?'

**lolife99** · 02-20-2011, 02:32 PM

Nate,... I posted in this thread,...
http://www.67-72chevytrucks.com/vboa...ad.php?t=43277

I should have posted here.
Lot's of confusion on where the "original location" of the tach wire hole should be in the firewall.
Since the 67-68 firewalls are different,... you have to address the 69-72 trucks only.

I don't have a picture out of the assembly manual.
Maybe someone else can reply.

72BlckButy · 02-20-2011, 04:26 PM

Bttt... Anyone?

Bueller,... Bueller?

**LockDoc** · 02-20-2011, 04:49 PM

-
Here are two different ones. the first one is a '67-'68 six cyl and i think one of the cables shown is for a cable driven tach. The second one is '71 six & V-8.

LockDoc

VA72C10 · 02-21-2011, 02:40 AM

Great info!!!

steelscout · 02-21-2011, 05:22 AM

subscribed, good info in this!

72BlckButy · 02-22-2011, 10:22 PM

Hey Leon... you don't by chance have UPC-1's diameter as it refers to the bottom of the picture posted above? Hole Dimensioning...

tcb-1 · 02-22-2011, 10:30 PM

take it back what I said a few nights ago. I used the dimple that's opposite of the 1-5/8 mark on the ruler. I looked at several factory tach rigs before I drilled at that location. forgot what size I drilled though. I believe I drilled a full size less than the grommet on the harness.

02-17-2011, 09:46 PM	#1
72BlckButy Tot Roddin' Join Date: Apr 2005 Location: Mid-MO Posts: 24,461	Those with factory tachs... check in! I'm looking to see if someone can post a picture of where the tach wire comes through the firewall. I'm trying to determine which dimple is the 'correct' dimple as there are 4 to pick from depending on the options installed. I "think" it's the 3rd from the bottom, but I want to make sure I'm selecting the correct one. Working on a project for my FIL. Please post a picture of your firewall. Thanks in advance guys! Nate __________________ -Nate 1969 CST SWB - Project Blank Slate (4.5/6" ECE Static Drop, 6-lug disc brake upgrade (manual), Billet Specialties Vintec 20x8.5 255/40 (F) 20x10 295/40 (R), 250 I-6) 1960 AMF Skylark - Tot Roddin' (Lowered with custom frame; soon to include custom push bar and interior) 2008 Silverado CrewCab 1LT (5.3L, 3:73, 4x4, LT1, Z-71, Towing Package)

02-17-2011, 10:59 PM	#2
ETsC10 Hand Crafted C-10 Join Date: Aug 2006 Location: Burien, WA Posts: 5,180	Re: Those with factory tachs... check in! Bump for ya~~ or should I say 'dimple'?

02-17-2011, 11:51 PM	#3
firedog Registered User Join Date: Jun 2000 Location: Festus, Missouri Posts: 1,005	Re: Those with factory tachs... check in! Speaking of the fil where are the pixs of his truck? Posted via Mobile Device __________________ SOLD 1968 Chevy SWB Fleet 350/350 combo Tach/tilt/buddy buckets Bagged/18" Wheels Black on Black Project "Pandemic" the Farm Rat 1927 Chevy Capitol Truck Rat rod '30 Model A Frame Dual Carb 5.3 LS http://www.67-72chevytrucks.com/vboa...d.php?t=804162 2007 GMC 4 DOOR 2WD BUILT 5.3 STAGE 3 CAM 93 TUNE LIFTED 22X12 WHEELS 33" TIRES 2023 Jeep RENEGADE Wifes ride

02-18-2011, 12:26 PM	#5
smorg007 Registered User Join Date: May 2010 Location: Redding, Ca Posts: 371	Re: Those with factory tachs... check in! My dimple where I drilled my tach hole was exactly where the picture shows it to be. Not quite as deep as those in the picture. I used the dimple as a punch hole for the 3/4 bit. There was even a perforated hole in my firewall material to match this location.

02-18-2011, 07:30 PM	#6
72BlckButy Tot Roddin' Join Date: Apr 2005 Location: Mid-MO Posts: 24,461	Re: Those with factory tachs... check in! Thanks for the post. What did you mean by 'not quite as deep?' __________________ -Nate 1969 CST SWB - Project Blank Slate (4.5/6" ECE Static Drop, 6-lug disc brake upgrade (manual), Billet Specialties Vintec 20x8.5 255/40 (F) 20x10 295/40 (R), 250 I-6) 1960 AMF Skylark - Tot Roddin' (Lowered with custom frame; soon to include custom push bar and interior) 2008 Silverado CrewCab 1LT (5.3L, 3:73, 4x4, LT1, Z-71, Towing Package)

02-20-2011, 02:32 PM	#7
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,701	Re: Those with factory tachs... check in! Nate,... I posted in this thread,... http://www.67-72chevytrucks.com/vboa...ad.php?t=43277 I should have posted here. Lot's of confusion on where the "original location" of the tach wire hole should be in the firewall. Since the 67-68 firewalls are different,... you have to address the 69-72 trucks only. I don't have a picture out of the assembly manual. Maybe someone else can reply. __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

02-20-2011, 04:26 PM	#8
72BlckButy Tot Roddin' Join Date: Apr 2005 Location: Mid-MO Posts: 24,461	Re: Those with factory tachs... check in! Bttt... Anyone? Bueller,... Bueller? __________________ -Nate 1969 CST SWB - Project Blank Slate (4.5/6" ECE Static Drop, 6-lug disc brake upgrade (manual), Billet Specialties Vintec 20x8.5 255/40 (F) 20x10 295/40 (R), 250 I-6) 1960 AMF Skylark - Tot Roddin' (Lowered with custom frame; soon to include custom push bar and interior) 2008 Silverado CrewCab 1LT (5.3L, 3:73, 4x4, LT1, Z-71, Towing Package)

02-20-2011, 04:49 PM	#9
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,818	Re: tach wire ? - Here are two different ones. the first one is a '67-'68 six cyl and i think one of the cables shown is for a cable driven tach. The second one is '71 six & V-8. LockDoc Attached Images __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - Last edited by LockDoc; 02-20-2011 at 05:14 PM.

02-21-2011, 02:40 AM	#10
VA72C10 VA72C10 Join Date: Mar 2008 Location: Midlothian, VA Posts: 25,267	Re: Those with factory tachs... check in! Great info!!! __________________ Looking for a 67-72 swb or blazer project in or around VA.

02-21-2011, 05:22 AM	#11
steelscout Words under my name Join Date: Nov 2010 Location: Lakewood, Washington Posts: 181	Re: Those with factory tachs... check in! subscribed, good info in this! __________________ 69 Chevy CST/10 "Project: Bloody Knuckles" my slow going project. 2010 VW Golf, daily driver Wrench Rookie

02-22-2011, 10:22 PM	#12
72BlckButy Tot Roddin' Join Date: Apr 2005 Location: Mid-MO Posts: 24,461	Re: Those with factory tachs... check in! Hey Leon... you don't by chance have UPC-1's diameter as it refers to the bottom of the picture posted above? Hole Dimensioning... __________________ -Nate 1969 CST SWB - Project Blank Slate (4.5/6" ECE Static Drop, 6-lug disc brake upgrade (manual), Billet Specialties Vintec 20x8.5 255/40 (F) 20x10 295/40 (R), 250 I-6) 1960 AMF Skylark - Tot Roddin' (Lowered with custom frame; soon to include custom push bar and interior) 2008 Silverado CrewCab 1LT (5.3L, 3:73, 4x4, LT1, Z-71, Towing Package)

02-22-2011, 10:30 PM	#13
tcb-1 Nothing to see here..... Join Date: Jun 2007 Location: Shawnee, KS Posts: 4,625	Re: Those with factory tachs... check in! take it back what I said a few nights ago. I used the dimple that's opposite of the 1-5/8 mark on the ruler. I looked at several factory tach rigs before I drilled at that location. forgot what size I drilled though. I believe I drilled a full size less than the grommet on the harness. __________________ Doug THANK YOU to our American Soldiers & Veterans - POW MIA "You will NEVER be forgotten". The democracy will cease to exist when you take away from those who are willing to work and give to those who would not. Thomas Jefferson



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