Mechanical to Electronic Tach conversion

[windrider50]

Has anyone tried to convert a early 70-ish tach from mechanical drive to the later electronic versions by adding the movement and circuit board?

I'm looking at the Edelbrock Performer EFI setup for my 72 454, and it requires a HEI distributor. I beleive when GM went to the HEI distributor on Vettes, it also went electronic tach.

 

[mrvette]

Yes, the '75-77 tachs will work and fit fine....those years came with HEIs in them....

GENE

 

[Robin7TFour]

hello, i am running a later model gm hei unit with an electronic tach. the tach assembly fit in perfect in the dash housing ,all the light and wires matched. biggest is you can't tell the difference in the two types.
i found mine on ebay, it wasn't working ,but with a new circuit board, it was like-new.

robin

 

[patsnitrovette]

i stilll need to do the same thing,since i changed over to fuel injection i have no speedo and tach.guess ill be looking for a newer tach also.

 

[zwede]

Up to, and including, 1971 the numerals were green, and then switched to white. If you want a stock appearing electric tach in a 71 or earlier you can move your old faceplate to the electric movement out of a 75-77. I did this several years ago and it works great. Bonus is you will probably get a higher redline on the earlier tach face also.

 

[JOliver]

Early Tachs 68-74s attached with screws to the main frame.The 75-77s attached with rivets to a coil and housing..it an be done only bad thing is the 75-77s had the coil style with the circuit boards the same boards that are notorious for going bad.Use them with a higher output HEI and you'll have problems.
But it is a cheaper way of doing it.
I offer a electronic conversion using a newer style tach unit..install it in where the mech. unit is and looks stock with wires coming out.


Jason
VetteInstruments@aol.com

 

[patsnitrovette]

joliver how much do you get for it and any pictures of it.