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

dlrobert95 · 09-05-2013, 06:13 PM

How much trouble would it be to put a factory tach in my '70 CST 10 if it wasn't originally equipped with it? It has the 7 gauge dash with an empty hole where the tach would've been.

tommys72 · 09-05-2013, 06:56 PM

Shouldn't be that hard. ..I had a lot of problems, but they ended up not being that bad
Posted via Mobile Device

71swb4x4 · 09-05-2013, 07:02 PM

Not tough.
It's been a while since I have done one but I believe if you want to add a factory tach to your existing cluster you will need a inner tin, tach, and printed circuit.
You can purchase a tach outer tin and tach wiring harness too.
If you don't want to buy an outer tin I believe you can cut a hole in the back of your existing outer tin if you want, and you can use a couple wires with spade ends for the tach wiring harness.

Edit: you need a tach lense too.

Andy4639 · 09-05-2013, 07:59 PM

If you want a stock tach,
Tach, lens, printed circuit board, and harness to fuse block and dizzy.
The harness as stated a couple of spade connectors and wire and your good to go.
U can find them on the parts board sometimes also but you have to be quick.

Prices:
36-1930- TACHOMETER 89.95
38-8010-PRINTED CIRCUIT $39.95
38-8002 INSTRUMENT LENS 29.95

dlrobert95 · 09-05-2013, 09:02 PM

I thought about this after the fact. Does the fact that I have an HEI distributor out of a later model make having a factory tach impossible, or would it be similar to hooking up a wire to the spade on the side of an HEI like the cheap-o sunpro tach I have right now? I'd love to have a factory tach, but not if it means going back to my old points distributor and coil. Providing that this can be done, I am planning on buying the parts from LMC truck. Is there a better source or should I stick with LMC?

71swb4x4 · 09-05-2013, 09:09 PM

Some people have had problems with an HEI burning up a "new" factory tach. I have run it without a problem.

There are many vendors who advertise on this site, and thus provide income to the site to keep it going for us. I would highly recommend using one of those vendors.

I believe the vendors with 5 stars advertise here: http://67-72chevytrucks.com/links/browselinks.php?c=2

Andy4639 · 09-05-2013, 09:17 PM

I have used the factory tach for over 15 years on mine with HEI. I have never had a problem with it. I also have herd people that burnt up tach's with HEI but for the life of me don't know how they did it other than hooking it up wrong to begin with. I just can't see how it burns one up but not another one. My HEI is no differant than yours are anybody eles for that matter.

The LMC post was not for u to buy from them at all, it was only showing u prices and what to look for. LMC has the best pictures of parts and it is nice sometimes to see the part in full. A good referance also.

Referance picture for you to see what it looks like.

**TBONE1964** · 09-05-2013, 09:28 PM

Quote:

Originally Posted by dlrobert95

I thought about this after the fact. Does the fact that I have an HEI distributor out of a later model make having a factory tach impossible, or would it be similar to hooking up a wire to the spade on the side of an HEI like the cheap-o sunpro tach I have right now? I'd love to have a factory tach, but not if it means going back to my old points distributor and coil. Providing that this can be done, I am planning on buying the parts from LMC truck. Is there a better source or should I stick with LMC?

If you are going to purchase aftermarket parts, check with a place called "The Filling Station in Lebanon, OR. The people that work there know much more about these trucks than LMC does. They have a very knowledgeable staff and they have better prices on many items.

fp1967 · 09-05-2013, 09:39 PM

I've been running a factory (not repo) tach with an HEI since 1987, I've put approx. 175000 miles on it, and haven't had a problem. I also had one other truck for about a year that I had a factory tach with an HEI and that one worked good also. I come on this site to learn about these trucks and find it interesting that some of the new tachs burn up with the HEI. If I ever have to buy a new one, I'll be researching more about what to do. I think I saw where somebody mentioned a filter?

09-05-2013, 06:13 PM	#1
dlrobert95 Registered User Join Date: Sep 2013 Location: Stephenville, Texas Posts: 4	Factory tach question How much trouble would it be to put a factory tach in my '70 CST 10 if it wasn't originally equipped with it? It has the 7 gauge dash with an empty hole where the tach would've been. __________________ 1970 Chevrolet CST-10 LWB; bedside toolbox; TH350 tranny (200-4R coming someday); 350 V8 bored .030 over, 280dur./.480 lift cam, Edelbrock Performer intake, Holley 750cfm Double Pumper carb, HEI distributor with MSD coil; full length headers feeding 2.5" true duals with 18" Cherry Bomb glasspacks. Everything else is factory original.

09-05-2013, 06:56 PM	#2
tommys72 Registered User Join Date: Jun 2012 Location: springfield mo Posts: 3,075	Re: Factory tach question Shouldn't be that hard. ..I had a lot of problems, but they ended up not being that bad Posted via Mobile Device __________________ United States Marine Corps 2000-2011 Iraq and Afghanistan veteran Just living life now and enjoying it and my wife, daughter and son

09-05-2013, 07:02 PM	#3
71swb4x4 Senior Member Join Date: Nov 2003 Location: Brookings, SD Posts: 10,497	Re: Factory tach question Not tough. It's been a while since I have done one but I believe if you want to add a factory tach to your existing cluster you will need a inner tin, tach, and printed circuit. You can purchase a tach outer tin and tach wiring harness too. If you don't want to buy an outer tin I believe you can cut a hole in the back of your existing outer tin if you want, and you can use a couple wires with spade ends for the tach wiring harness. Edit: you need a tach lense too. __________________ Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.

09-05-2013, 07:59 PM	#4
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: Factory tach question If you want a stock tach, Tach, lens, printed circuit board, and harness to fuse block and dizzy. The harness as stated a couple of spade connectors and wire and your good to go. U can find them on the parts board sometimes also but you have to be quick. Prices: 36-1930- TACHOMETER 89.95 38-8010-PRINTED CIRCUIT $39.95 38-8002 INSTRUMENT LENS 29.95 __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. Last edited by Andy4639; 09-05-2013 at 09:18 PM.

09-05-2013, 09:02 PM	#5
dlrobert95 Registered User Join Date: Sep 2013 Location: Stephenville, Texas Posts: 4	Re: Factory tach question I thought about this after the fact. Does the fact that I have an HEI distributor out of a later model make having a factory tach impossible, or would it be similar to hooking up a wire to the spade on the side of an HEI like the cheap-o sunpro tach I have right now? I'd love to have a factory tach, but not if it means going back to my old points distributor and coil. Providing that this can be done, I am planning on buying the parts from LMC truck. Is there a better source or should I stick with LMC? __________________ 1970 Chevrolet CST-10 LWB; bedside toolbox; TH350 tranny (200-4R coming someday); 350 V8 bored .030 over, 280dur./.480 lift cam, Edelbrock Performer intake, Holley 750cfm Double Pumper carb, HEI distributor with MSD coil; full length headers feeding 2.5" true duals with 18" Cherry Bomb glasspacks. Everything else is factory original. Last edited by dlrobert95; 09-05-2013 at 09:08 PM.

09-05-2013, 09:09 PM	#6
71swb4x4 Senior Member Join Date: Nov 2003 Location: Brookings, SD Posts: 10,497	Re: Factory tach question Some people have had problems with an HEI burning up a "new" factory tach. I have run it without a problem. There are many vendors who advertise on this site, and thus provide income to the site to keep it going for us. I would highly recommend using one of those vendors. I believe the vendors with 5 stars advertise here: http://67-72chevytrucks.com/links/browselinks.php?c=2 __________________ Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.

09-05-2013, 09:17 PM	#7
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: Factory tach question I have used the factory tach for over 15 years on mine with HEI. I have never had a problem with it. I also have herd people that burnt up tach's with HEI but for the life of me don't know how they did it other than hooking it up wrong to begin with. I just can't see how it burns one up but not another one. My HEI is no differant than yours are anybody eles for that matter. The LMC post was not for u to buy from them at all, it was only showing u prices and what to look for. LMC has the best pictures of parts and it is nice sometimes to see the part in full. A good referance also. Referance picture for you to see what it looks like. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. Last edited by Andy4639; 09-05-2013 at 09:31 PM.

09-05-2013, 09:39 PM	#9
fp1967 Registered User Join Date: Aug 2012 Location: U.P. of Michigan Posts: 115	Re: Factory tach question I've been running a factory (not repo) tach with an HEI since 1987, I've put approx. 175000 miles on it, and haven't had a problem. I also had one other truck for about a year that I had a factory tach with an HEI and that one worked good also. I come on this site to learn about these trucks and find it interesting that some of the new tachs burn up with the HEI. If I ever have to buy a new one, I'll be researching more about what to do. I think I saw where somebody mentioned a filter?



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