I am the proud new owner of a 1970 Coupe. Wanted a vette for years and finally found the one I was looking for.

One item that I am trying to fix is the tachometer. The previous owner dropped a ZZ4 crate engine and installed a electrical ignition (thankfully he kept the original engine for the car). I understand that the stock tach is mechanical and I wanted to see if any of you guys knew of a converstion part to make the tach work with the updated ingition?

Thanks,

Mike

Hey Mike - welcome to C3VR...!!! It's great to have another '70 in the crowd!

I don't have an answer for you on your tach question, but I'm sure there is someone out there who does.

You would either need a electronic c3 tach. or a way to turn the mechanical tach at the proper speed, ie: tach drive dist.. i beleive that later c3's had electronic tachs. you may be able to rework your tach to use the electronic guts. or there may be someone that makes this item but i would be very supprised. you would be better off finding a tach-drive dist. and installing a pointless setup in it.

Mid America sells the tach drive set up for the HEI but it will cost you 5 and a half bills
tom

Hi Mike, Welcome. If the original distributor is with the other engine, you can get an electronic conversion that goes inside it from "Pertronix". It's a very easy conversion and only costs about $100. Unless the previous owner put in an electric tach, then you would need to find an original mechanical drive tach.
Good luck, Mark

The tach for a 75 is identical looking (except for the white lettering, which is almost indistinguishable) and is designed for an electronic tach. A used one will cost less than a new distributor, tach cable, and pertronix.
Good Luck.
K & M Restorations.

Hi there,

I have a pertronix ignition and I am not all that happy with it. Lectric Limited has what looks to be a sturdier version of the pertronix unit. When this one fails that is what I will go to. (This is unit number two and it has an intermitant miss that I believe is due to a wire break inside the module. Unit one the magnets just fell out into the distributor. Made a hell of a mess.)
If you are carefull you can take a 75 tach mechanism and install it in your 70 tach. The ZZ4 HEI is a great unit and you should try to keep it if you can.

Alex

here is something you may really like. Take a look at the photo below. Please note these are silver faced gauges, but you can get black faced ones as well. This install went very smooth using an aluminum plate that I cut out as a large washer so to speak that I riveted to the back of the stock cluster, then slipped the 5" gauges in place. This allows you to ge electronic on the speedo and tach for smooth trouble free operation. Plus, they sweep when you turn the key on like a C5, which is really cool!

This will also set you back about $500 and a full weekend of goofing around with it, but you will find it to be one sweet mod (that is tach and speedo swap).