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Can any of you guys help with info on converting my GT cluster tach to read right in a v8 conversion. Thanks in advance for any help.

From the FAQ:

9.4 How do I modify my tachometer?

All later tachometers are basically the same. On the circuit board is snap-in piece that goes in one of two slots. No clip = 4 cylinder, clip in upper slot = 6 cylinder, and clip in lower slot = 8 cylinder.

For Vega tachometers, the circuit board must be modified. One recommendation is to put a 1000 ohm potentiometer in-line between the meter and board, then adjust the pot until the reading on the meter is what you want (compare it to an underhood tach). Another is to add two 1u50V capacitors to the board.

A diagram of the board with modification instructions can be seen at: http://ia.yimg.com/a/77ab29b0/h/50b6570/tachv8mod.jpg

If you decide to just get a V8 tachometer from a donor car, you must also replace the capacitor on the coil trigger wire.


Unfortunately that picture link no longer works. However I swear I just saw that picture a few days ago but my brain is too fried to remember where...

And there it is! Zeke you're psychic!

Here's a local copy:

i sent mine to redline gauge works somewhere in ca. they did the v8 conversion and updated the innards with something called vdo electronics cost 194.00 in dec. of last year and it works great 1 wire and it plug stright iotn my 6al msd box easy for a electric dunny like me all i got is a phone # i can fine right now 661-259-8891 good luck!

Thanks guys for the info. Looks to be pretty simple.

A member here, Tim McCabe---who owns the green '73 Vega(Kermit) with the TPI 305 and T-5 tranny---- sweet, very sweet... does this conversion.

Not only does he convert it...... but he calibrates it also. Most all the GM tachs are way off... especially on the high end. He does a great job.

I will keep that in mind. Thanks!