distributor
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Just buy a used late 60's / early 70's C3 tach and have it rebuilt (or do it yourself). Most of the low-dollar items on the web are poor quality junk. Well made products are way too pricey. If all the parts are in the used dizzy and it isn't rusted solid, it can be rebuilt.
Melting Slicks
Joined: May 2012
Posts: 2,192
Likes: 343
From: Allenton Wisconsin
Here on the CF parts for sale there are tach drive dist coming up for sale all the time around $100 to $125, they sell electronic conversions for the point distributors that work excellent. When I swapped mine over I went with the Crane Fireball, another good choice is Pertronics, they sell for under $100. So for about $200 you are into a tach drive with electronic ignition. Just because I enjoy spending other peoples money, a electronic ign requires a different ign coil designed for electronic ign, also this would be a great time to have the timing curve reset on your new setup for better performance. Going this route allows you to use the OEM chrome shielding that comes stock on any 69 that came with a radio.T
Tech Contributor
Joined: Aug 1999
Posts: 14,375
Likes: 6,375
From: At my Bar drinking and wrenching in Lafayette Colorado
Drop me an e-mail request, and I'll send you the test results of testing I did with Hot Rod Magazine several years ago comparing aftermarket electronic systems to plain ol' stock points distributor in a street driven engine.
Lars
V8FastCars@msn.com
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Thread Starter
4th Gear
Joined: Oct 2017
Posts: 4
Likes: 0
Why...? The stock points distributor, correctly set up, will run circles around any out-of-the-box "electronic" distributor, and good points will run without adjustment for 30,000 miles.Why do you want to go with an inferior aftermarket "electronic" system? Is your car too fast, so you need to slow it down..?
Drop me an e-mail request, and I'll send you the test results of testing I did with Hot Rod Magazine several years ago comparing aftermarket electronic systems to plain ol' stock points distributor in a street driven engine.
Lars
V8FastCars@msn.com
Drop me an e-mail request, and I'll send you the test results of testing I did with Hot Rod Magazine several years ago comparing aftermarket electronic systems to plain ol' stock points distributor in a street driven engine.
Lars
V8FastCars@msn.com
Melting Slicks
Joined: May 2012
Posts: 2,192
Likes: 343
From: Allenton Wisconsin
Any points style distributor has wear and causes point dwell variation. When I was a teenager [5 decades ago] working at a Shell station they had a Sun 1020 with an oscilloscope that you could watch the dwell variation on new engines [3 to 7 degrees, GM the best then Ford, Mopar the worst]. Now here we are 45 years later, the shafts and bushings are worn and those distributors have even more dwell variation. So unless you either put a new shaft or have the old one built up and remachined and new bushings installed the old distributors probably have 5+degrees of point variation which causes engine misfires at higher rpm also known as power loss, whereas replacing the points with an electronic pick-up is in my opinion the easier considering the electronic pick-up doesn't care if the distributor shaft has any wobble to it. For the 4 years that I ran the Crane Fireball electronic pick-up in my 69 350 300hp with over 90k miles and buzzed that engine until the valves floated it never had a misfire and started just by touching the key after warmed up, the Holley spreadbore didn't have a choke but still started and ran better that with the Q-jet that ended up in the trash.T
Last edited by terrys6t8roadster; Sep 14, 2018 at 08:32 AM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Most of the distributors purchased from auto parts stores or on-line are junk just waiting to fail. The point of purchasing a used GM (tach drive) distributor is twofold:
1. It has the tach drive necessary to operate the tachometer;
2. It is designed with the capability of being refurbished. Bushing and gears can be replaced, if necessary. In short order, a used GM dizzy can be rebuilt to like-new or even better-than-new condition.
Unless your engine has been reconfigured with a position sensor at the crankshaft, any electronic ignition signal is triggered off the distributor output. So, the dizzy needs to be in good shape either way.
1. It has the tach drive necessary to operate the tachometer;
2. It is designed with the capability of being refurbished. Bushing and gears can be replaced, if necessary. In short order, a used GM dizzy can be rebuilt to like-new or even better-than-new condition.
Unless your engine has been reconfigured with a position sensor at the crankshaft, any electronic ignition signal is triggered off the distributor output. So, the dizzy needs to be in good shape either way.
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 780
From: Eustis ( Area 51 Bat Cave ) Fl
Any points style distributor has wear and causes point dwell variation. When I was a teenager [5 decades ago] working at a Shell station they had a Sun 1020 with an oscilloscope that you could watch the dwell variation on new engines [3 to 7 degrees, GM the best then Ford, Mopar the worst]. Now here we are 45 years later, the shafts and bushings are worn and those distributors have even more dwell variation. So unless you either put a new shaft or have the old one built up and remachined and new bushings installed the old distributors probably have 5+degrees of point variation which causes engine misfires at higher rpm also known as power loss, whereas replacing the points with an electronic pick-up is in my opinion the easier considering the electronic pick-up doesn't care if the distributor shaft has any wobble to it. For the 4 years that I ran the Crane Fireball electronic pick-up in my 69 350 300hp with over 90k miles and buzzed that engine until the valves floated it never had a misfire and started just by touching the key after warmed up, the Holley spreadbore didn't have a choke but still started and ran better that with the Q-jet that ended up in the trash.T
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 780
From: Eustis ( Area 51 Bat Cave ) Fl
Race Director
Joined: Mar 2017
Posts: 11,930
Likes: 4,497
From: Virginia
I purchased an AC Delco 93440806 HEI distributor from eBay for half the going price. I was told it was a never run, ZZ4 take-off, and that's what it looked to be. It's worked great for my wife's 79, and looks like it belongs there, though I did have to change to an adjustable vacuum modulator, and add shims on the gear. Make sure the gear itself is compatible with your camshaft if you go this route, or get a gear that is.
I had points in my Corvair. I'd never complain about HEI, but the ignition in my LS-powered truck works flawlessly, too.
EDIT - Do take Lars up on his offer to email you his timing papers. HEI or not, following his instructions with a digital timing light and some tuning will make your car much happier.
I had points in my Corvair. I'd never complain about HEI, but the ignition in my LS-powered truck works flawlessly, too.
EDIT - Do take Lars up on his offer to email you his timing papers. HEI or not, following his instructions with a digital timing light and some tuning will make your car much happier.
Last edited by Bikespace; Sep 14, 2018 at 11:24 PM.