LeMans Pete

I'm looking to replace the TI system in my 1969 350 with an HEI unit. Will any HEI unit drop right in? Will it all fit under the ignition shielding?

4-vettes

It'll drop right in. Your tach cable won't have a home. Your ign. Shielding won't fit. Although you can get Shielding for a 75-77 that will.

Pop Chevy

You can buy a tach drive HEI

LeMans Pete

I'd get a mechanical tach drive for that tach cable I'm also curious if a unit like this (https://www.topstreetperformance.com...ach-drive.html) will fit under the stock 1969 ignition shielding.

Yes sorry, should have stated that. Mechanical tach drive HEI indeed. I'm seeing quite a few options, any known to fit under the stock shielding?

c69vete

There are some small head HEI dizzys out there. They would allow the use of stock chrome. The large head dizzy will not fit inside of the 69 chrome housing. Later years used only the top cover. Your housing can be cut to clear the cap and has been done many times.

Barry's70LT1

I replaced the TI in my '70, due to it failing twice over the years. I kept my original TI distributor and I'm using a HEI module remotely mounted and a HEI remote coil mounted in place of the TI coil. This setup works better than the TI ever did.

LeMans Pete

I’m hoping to replace it with this unit to fit as-is under the stock shielding: https://www.topstreetperformance.com...ach-drive.html

LeMans Pete

Hey Barry,

Tech is telling me the dizzy is bad as well. I plan to send both the dizzy and amplifier off to be restored and then sell them. It’s a NOM car, so I’m not too concerned about the originality of it, just want a machine to cruise in.

Bikespace

What NOM engine do you have now? If you don't need to fit under the shielding, and if you can convert to an electronic tach, that opens up options.

LeMans Pete

It's a CE motor from 1971. I would strongly prefer it to fit under the shielding to maintain a stock appearance, and who doesn't like the look of chrome.

I am not interested in converting to an electronic tach, that opens an entirely new can of worms. Just looking to replace the existing TI distributor with a mechanical tach driven HEI unit.

Barry's70LT1

That looks to be a bit on the "tall" side to fit under the sheilding, also, the plug wires add more height, can you get an overall height dimension, with plug wires. Does it use a regular canister type coil.
If it fits, it should be a good solution.

Barry's70LT1

Is it a " worn out" thing with the orig dist, or is the mag pickup shot, or both.

LeMans Pete

Hey Barry, that's what I'm wondering. The overall height from the distibutor flange to the top of the cap is 8-1/4". I don't have my distributor near me since it's at the shop, I'd be curious what the height is on the stock unit.

Supposedly both the mag pick up and the pulse amplifier are shot. I'm a little weary, but honestly I've been fighting this battle for a year and I'm tired. Very reputable shop, and with the NOM, I'm willing to just go ahead and change it to an HEI unit if they say that'll get me running.

stingr69

David Ray -ignitionman conversions

You might want to call this guy. He does conversions to small body distributors to HEI and recurves them as well. Been doing it forever. I have never used him but a lot of others do.

pgtr

Or consider installing a Pertronix or similar electronic conversion kit. It's a cheap, easy project, fits under the stock cap, and retains the stock distributor (with mech. tach drive).

Barry's70LT1

That sounds like a good idea, then you don't have to mess with the sheilding. Question... The Pertronix kit I assume is made to replace the points, since the TI distributer does not have a breaker plate, will this kit still work?

You can convert a TI distributer to a points distributer very easily, however you need the breaker plate.
I guess one option would be to convert to points, easily done. Stay old school.

wwiiavfan

I think I have read on these forums that the Pertronics conversion has questionable reliability?
Cant say from first hand experience, but it bears mentioning.

In 2021, I didn’t want to fiddle with the points on my ‘71, so I took a chance and bought a cheap ($56!!) tach drive HEI off eBay from KMJ Performance, fully expecting it to be a POS, but for $56, what the hell, right?
Well, other than a glitch that was probably my fault (melted a connector from not being fully plugged in), it has been trouble free for several thousand miles.
This was a standard size HEI, so won’t fit under your early ignition tins, but I think that outfit also has small cap HEI’s.
Anyway, you mileage may vary, take it for what it’s worth.

stingr69

Fix the mag pulse in the TI distributor and use it to fire a remote CD box is also possible. I run a very old obsolete magnetic trigger conversion with an equally old Crane multi-spark CD box in my Camaro and it works perfectly with a stock points coil. Pick up the used boxes on Ebay for about $100 these days because all the cool kids are ditching them for computerized EFI setups. If you want to go there I can assist.

ctmccloskey

My 1968 C3 with it's 427 came with a factory T.I. system. It worked well but being paranoid I wanted to upgrade it to a MSD 6AL ignition system. I bought the MSD parts and installed them without any problems. I have a MSD 6AL, Blaster 2 Coil, Super Conductor wires and a MSD Digital retard box. The Digital retard box simply allows me to pull up to 20* of timing while cranking which makes the 12.25-1 Compression ratio engine crank like a Chrysler.

At a Corvettes@Carlisle I then met a gentleman named Dave Fiedler who is also an expert in the T.I. systems as well as an E.E.. Dave designed a new control board that resolves many of the previous problems. I sent him my parts and he overhauled them for me. I then vacuum packed the newly rebuilt parts and put them on the shelf in my garage. I bought a new control board and it does in fact work very well.

If you do buy a new MSD Mechanical drive distributor be sure to take it to a shop that can verify the timing curve it has.

pgtr

Huh. I installed a Pertronix on mine back in the 90s. After 20+ years it still works.. Fits under the stock cap and retains the tach drive - most anyone would never know it was there. No more points setting, no more changing/filing points, and no more adjusting of the dwell. While I had the distributor out I put in new advance springs spec'd for an L46 and adjusted the bushings on the shaft for the correct gap.

Back in the mid 70s or so there were a lot of companies offering retrofit electronic ignition conversion kits as the manufacturers were switching new cars to electronic ignition (and gas prices were increasing and emissions were becoming more of an issue). Obviously the general market has dried up for such kits. I don't know off hand if there are other options today besides Pertronix.