fgp73

I have a '73 Vette that had its distributor replaced with a non tach drive distributor. I sure would like to have it replaced with one that will drive the tachometer. Is there a consensus on what type would be best?

Any info would be helpful

Ironcross

Check E Bay for a replacement HEI distributor with a tach drive. They work and are ridiciously cheap...about $125.00 or there abouts...You cant go wrong with these distributors. The competitions distributors are nearly double and could be the same ones with a different color cap....There is a E Bay seller.....

71_S-Ray

I was thinking about buying this one through Summit, but now I'm considering pulling all the gauges and going electric to them all, so who knows what I'll eventually do.

http://www.summitracing.com/parts/MSD-8572/

baxsom

the one on ebay is called the dragon fire by Allignition.

excellent unit

fgp73

like this?

http://cgi.ebay.com/ebaymotors/Corve...1%7C240%3A1308

fgp73

Forgive me if this is a dumb question, but should I replace the points system with an electronic distributor?

Paul71LT1

The answer is YES! If you buy the tach drive HEI from e-bay you will have an electronic version with no points. I bought one a couple years ago for about $150 from e-bay and it worked perfectly in my '73.

temvette72

I put an E bay unit in my 72. Works perfect and a bargain price. Just run a good 12 volt power source with a large gauge wire. I ran the hot wire directly from the fuse block. It has adjustable vacuum advance, but it was perfect out of the box after I set the initial timing. I highly recommend it!

Temvette72

PeteZO6

All the above advice about using a tach drive HEI distributor is excellent. The only caveat I would offer is that if you ever plan to have your car judged on originality, you will have points deducted for a non-original part. Ugh! I can't believe I'm saying to use a points distributor! Just something to consider as you replace the distributor.

Pete

Ironcross

Yep, exactly what I suggested....and as you can see over three times as much for the {brand name} stuff and works the same....With prices like that, no wonder they have so many company race cars, you bought them.....

get the e bay unit.....

CheezMoe

Ditto. Best deal out there and performs flawlessly!

Dustup7T2

This is one subject I can straddle both sides: mech drive and electronic.

I've always run wired tachs with no problems. They work great and keep me informed.

When I bought my '72, I inherited a non-OEM distributor (Mallory Unilite) with a mech tach drive and connected to an MSD 6AL box. Cool. It too, works great.

First mech drive I ever owned and maybe it's just the thought there's a cable spinning instead of a wire sending pulses that reminds me of old-school race cars.

These old Corvettes had some fascinating engineering developed into them. I love this stuff (but only when I'm not mutterin' bad words under my breath over another PITA issue).

jordan89

ECKLERS has Tach driven MSD distributors, although they are expensive.

oldboat

i put a hei tach drive distributor on my '69 about fourteen years ago. every ignition problem i ever had immediately went away. it is one of the best things i have ever done for my car.

UBETRUN

Can the ebay tach drive distributor be changed to a bronze gear for a mechanical roller cam? I know I can order the bronze gear for other distributors, just don't know if they are all the same.

7T1vette

Perhaps you should test out the (mechanical) tach in your car to make sure it works before buying a tach drive distributor. If the cable is still attached, just hook a small cordless drill's chuck up to the other end of the cable. Run it at a very slow speed until you determine if you are rotating the correct direction. Reverse if necessary. Then run slow again and watch indicator as you increase speed. It should be smooth, steady at a constant drill speed, and work throughout it's range. If the tach doesn't work, then you have to decide whether to fix the mechanical one or switch to electric.

fgp73

That's a good idea. I'll do that today and report back. The cable is there right by the distributor. Do you know for sure which would be the correct way to spin it?

7T1vette

I think it's clockwise; but to be honest, I can't remember for sure. But running the drill at low speed the wrong way should not do any damage...that would just simulate backing-up (which should free-spin, rather than moving backwards).

fgp73

it was counterclockwise (loosen on the drill) and it did work (the tach that is)...thanks...next step is to change out the distributor

jackson

All of the tachdrive hei I've seen are clones of GM hei which has 0.491" diameter shaft. You'd best ask the ebay seller for dimensions. You'd best do some searching on gear material. And you'd best ask your cam maker what kind of gear other than bronze can be used with your cam. Street cars should avoid bronze & avoid polymer if at all possible. Most cams (billet steel & iron) can use melonized GM gear p/n 10456413 which fits 491 shaft. There's been lotsa threads on this very matter ... search. That's the straight dope ... ask the suppliers when they aren't itching to sell ... you'll likely gets lotsa different opinions here & some aren't well grounded in practical experience.