popeye

iTrader: (3)

A friend has a 69 vette and is wanting to install a ls1 and auto trans. The speedo and tach are both mechanical drive.

I have done a search and found an extension housing for the transmission is available, is there a way to get tach working?

garys 68

iTrader: (1)

Some people have bought later year vette electronic tachs and change faceplates for engine swaps. However, I'm not sure if the vette electronic tachs can be set for the LS 4 cylinder signal.
My solution:
I found a tach with the same sweep as my original 68 tach.
The Isspro in the link below matched perfectly. It took about 20 minutes of cutting on the Isspro and vette housing to make it fit, but now I have the OEM appearing electronic tach working for my LS motor.
BTW, the 2 screw mounting holes in the front of the Isspro match the mounting holes in the vette tach faceplate exactly and the vette needle presses on the Isspro too.
http://www.isspro.com/proddetail.php?prod=R85100

busta9876

iTrader: (3)

PCM can be programmed to make tach signal 8 cylinder. I did this to my PCM to keep from cutting the wire on back of my auto meter 5" tach.

busta9876

iTrader: (3)

If dead set on using cable drive tach, might be able to make one of those Cabl-X devices work. They are used to take electronic speed signal in, and make cable speedo drive out.

Using TACH signal, some programming, and help from the manufacturer you might be able to drive you're cable tach at correct speed.

popeye

iTrader: (3)

Thanks for the info. I talked with Charlie today and now he wants to keep it as stock as possible .

garys 68

iTrader: (1)

Sounds good to me.
I'm using the stock speedo, modified (but stock appearing tach), oil, temp, and ammeter gauges on my 68 vette.

busta9876

iTrader: (3)

This topic sparked my interested and I emailed the company that makes the Cable X for driving speedo's from a vss signal. They said YES it would work to drive the tach using the PCM's TACH signal. Said to call for more info.

Lee Own @ 1-800-643-5973

Abbott Enterprises
Pine Bluff, AR
www.abbott-tach.com
870-535-4973

popeye

iTrader: (3)

Thanks for the info. I should have said more. Charlie wants to start putting it back original.

Here is a little info about the car. I bought it in late 1983-early 1984 had been through a ditch and had some fiberglass damage. It is an original 427-390hp car with ps, pb, auto with 4.11's and a/c. He called me and was wanting to know about the original engine. It was gone when I bought it. I have no idea where it could be at. I tried to talk him in doing a ls engine change, he said ok then talked with some hardcore vette guy and convinced him that the only thing to do was return it to the "original condition".