In-dash tach for a 6

[64Short]

I would like to get the after market tach off my column and go to an in-dash. All the retros that I can find state they are for V8s only. I have a 6. Talked to D&M and they could not help me. Any suggestions?

[DPowers]

JC Whitney
http://www.jcwhitney.com/illuminated...wx?filterid=j1

http://www.persh.org/pickup/TachDash.htm

[64Short]

Thanks DP, that is an option. I would like to stay with the factory look is why the retros were attractive. ANYBODY ???

[HEI451]

From info on this, and the 6066 sites, I am led to understand that the larger series trucks that had the V6's, C40, C50 and C60, had the factory tach in the dash. I haven't run across one of these trucks yet, but I am always looking.

The only other way to get the factory look would be expensive, in that a stock V8 tach would need to be obtained, and the movement behind the facia would need to be changed, to an aftermarket one, to make it all work with the V6.

The aftermarket tachs that are for 4/6/8 use a series of resistors to change the signal input, and changing the number of resistors sets the signal for the different number of cylinders. Some tachs use soldered in resistors that must be cut to change the signal, others use a rotating switch and resistors built into the printed circuit of the tach.

I'm still researching the whole mess, but, if a stock facia could be obtained for the tach in the pictures above, that just might be the best and easiest way to get a stock look tach for our V6's. The facia on a stock tach is silk screened in with ink, usually water soluble. but, a clever graphics person, or possibly computer program, could reproduce the correct facia "decal/sticker", and a simple aluminum or steel thin sheet could be cut into the correct backing plate, and mounted to the aftermarket tach.

Complicated, but not that complicated.

[tkeduk8r]

you could buy a brand new repop sun tach LINKY and just take the mechanicals out and place into your tach dash... you get 8k tach AND can easily change to 6 cyl settings.... Thats what I am planning on with my 292 build.... should work sweet.... hope that helps...
--Mike

[HEI451]

Red line for the latest 305 and other V6's was a whopping 3,800 rpm's, earlier ones down to 3,200 to 3,400 on a good day. The V6 tachs were 5,000 scale, no higher.

[chevyrestoguy]

Originally Posted by tkeduk8r

you could buy a brand new repop sun tach LINKY and just take the mechanicals out and place into your tach dash... you get 8k tach AND can easily change to 6 cyl settings.... Thats what I am planning on with my 292 build.... should work sweet.... hope that helps...
--Mike

I have been exploring this option as well.
A lot of folks don't know that Sun produced our truck's tachs for GM back in the day. They shared the same faceplate shape as the aftermarket Sun "half-sweep" tachs. I have not had a chance to look closely at the re-pop Sun tach that Mike listed, but I am almost certain that it will interchange into our dashes. You'll have to remove the outer case (or cup), but once that's off, you can see how GM secured the factory tachs to the clusters, and I can almost guarantee that the re-pop tach has fasteners in the exact same position. GM was SO GOOD at utilizing the same parts through all of their model lines that interchangeability is a breeze. The only drawback that I can see with the re-pop tach is that the coloring of the faceplate has white numbers over a black background, where the stock GM tachs had green numbers. I am trying convince one of the gauge overlay companies to produce an overlay with green numbers, but haven't gotten an answer yet.

I believe that the re-pop Sun tach has a switch to select 4,6, or 8 cylinder, so that solves your 6 cylinder issue. I plan on doing this swap in the next few months, and when I do, I'll make a very detailed instruction in my build thread.

If you want to see what I meant about how good GM was at interchanging parts among their brands, check out my '64 build thread where I used a vacuum gauge out of an Oldsmobile and made it look 100% factory Chevrolet for less than $30. Gotta love GM!

[HEI451]

A note about the earlier Sun tach's, they require a sender to get them to work correctly, senders are engine cylinder number specific, so, if yo find an early Sun tach on places like E-Bay, be advised, they will need the correct sender to make them work.

That said, the sender uses two AA batteries inside it to power it, and the tach up. The original batteries were made as "Mallory", NOT the ignition company, but the special metal used inside them. Regular AA batteries will work in these senders, but the life span can be reduced with some AA types.

What I do with the sender power is to NOT use the AA batteries in them, but use a simple, inexpensive DC to DC voltage inverter, one that has the right voltage, and is sold by Radio Shack and other electronics stores. This way, the sender powers up when the ignition switch is turned on,,and the tach power is supplied by the vehicle battery, NOT batteries inside the unit. There would also be no dead batteries to stop the tach.

chevyrestoguy brings up a great point, there are those early Sun, and later Sun Super Tachs that have the 4-6-8- switch already in them, those would be the ones to try to obtain and use, as they do not need a separate sender, they just hook up with 4 wires, 12 volt power in, ground, signal from the coil negative terminal and light feed.