djb68

Previous owner converted the distributor to an HEI and had the tach on the steering column. I am going to convert the C3 tach to an electronic tach from Zip. According to the Zip video, the tach has to be calibrated and to do so, you have to purchase a $50 conversion signal generator. I really don't want to spend an additional $50 for something I will only use once. Anyone know if you truly need to calibrate the a tach?

carriljc

djb68
Watch this video. This guy just uses a 12 v battery to set zero. Pay attention to NOT wiping the tach surface with anything other than a SOFT DRY TISSUE, or just leave it alone...... that lettering is really, really delicate...... don't use water, nor windex, nor anything else..... NOT KIDDING.

djb68

Thank you

carriljc

You're welcome. Let us know how it goes. I actually installed a 76 tach in my 68 and it's one of my favorite mods. Made future changes easier. I had to buy a tach board too so it ended up costing me about 170 bucks....and that was 20-21 years ago.....

Dale Scribner

I just finished converting my C2 stock tach drive distributor to accept an Edelbrock Pro Flo 4 electronic EFI distributor top. See pics.

Machined stock bowl to fit EFI


Tapped hole partern alowes top to be positioned anywhere.


Installed, see tack cable position.

carriljc

Dale Scribner
Wow. Impressive. Did you have to machine the cast iron? And fabricate that collar? Is the collar screwed onto the cast iron? Very nice.

69ttop502

I have installed 2 of those Zip tach conversion kits, and they both needed calibration. I have the calibration tool I bought from Willcox years ago. I would be glad to send it to you as I have done for other members over the years. Just cover shipping and will be glad to do it.

Bill

PWPOOP

I installed the Zip tach & all I had to do was to put power to it & set the needle to zero RPM. It is pretty darn close, if not dead on, to what my timing light reads for RPM. I also thought I would have to get the tool, but I guess not.
Darin

Rescue Rogers

You can do it with a timing light if it has a tach built in or use the tach that was on the steering wheel to calibrate by with your engine running......
And to add that the tiny rheostat is very easy to break. Mine fell apart while adjusting it so I brought it to work and soldered some 12 inch leads and a rheostat with a **** on it so I could do it while it was installed.

69ttop502

Good to know!

Dale Scribner

No, I machined off the cast distributor bowl and turned down the diameter to fit the Edelbrock top. The Edelbrock top is screwed onto the cast base. I drilled and tapped 12 10-32 holes into the cast and added another set of 4 holes to the top piece. I had to use the original C2 shaft as the Edelbrock for some reason is a bigger diameter. This allows me to rotate the top to wherever I need it in relationship to the bottom, and screw it down.Over all, it is was a lot of work but in the end it was worth it and a lot of fun, especially when it fired up the first time.

djb68

Thank you very much for the offer to loan me your calibration tool 66ttop502.
I am on a business trip right now and haven't ordered the conversion kit yet.
I'll reach back out to you when I get ready to install the conversion kit.

djb68

Wow
I'm not that mechanically inclined.
And my engine is no where that clean.

Dale Scribner

It is clean because it is new install. 383, tremec 5 speed 336 rear end, 4 wheel disc brakes and Pro flo 4 EFI, Bordeson power steering and AC, factory but modern compressor. Only have a few hours on it. Took it out for a putt today and at 70 MPH we were turning 1800 rpms. I am really happy with this combination. I had been stockpileing parts for 7 years and finially got it done. Next, front suspension rebuild. It is a joy to own one of these and be able to still work on it a 81 years old.

drspencer

That's a slick setup.

Do you know if that same rig would fit under the stock hood of a base model '71 C3?

Thanks

Dale Scribner

It might, I used a drop down air filter base and tilted it forward by making a tapered ring and welding that on the base. It has good clearance on a stock C2. The Edelbrock IFI intake was actually lower than the original C2 high performance intake. Edelbrock support might be able to tell you, they did for me. Dale

drspencer

Any opinions on the ProFlo 4 vs. a well-tuned Quadrajet?

Thanks

Dale Scribner

I haven't touched a quadrajet in 40 or 50 years. I had a Holley double pumper on the engine I took out, a 1970 365 HP engine. That Holley was forever out of tune and was a leaker. After going to the Edelbrock Pro Flo 4 there is no comparison. Very easy install and setup. The performance shop that did the dyno testing on my engine before I installed it were very happy with the Pro Flo 4 and how easy it was to run through the setup using the app and my phone via bluetooth. They said they wanted to become a dealer after they were finished. This car now fires up immediately and doesn't smell like gas like the Holley carb did. I believe Holley now makes an EFI similar to Edelbrock and they make a tach drive distributor. Their front runner system is also very nice. Hood clearance was one reason I purchased the Edelbrock. The air cleaner cleared on my C2. Dale
I tried a 3" air filter but no go, so 2" it is.

Rescue Rogers

I can compare it to the sniper....Holleys Quadrajet was much better....16 mpg and no issues...dont buy a sniper

drspencer

Thanks for the response, Dale.

Fuel injection has tremendous appeal to me, but I know very little about aftermarket EFI systems.