Brand new to the site.
Thanks ahead of time for any hints and advice.
Bought the car 3 years ago, but now retired with time to make her mine.

'67 400 ragtop .... year correct 400 block, rebuild .030 over 3,000 miles ago, Holley 650 double pumper, Edlebrock Performer intake, Borla exhaust, Be Cool cooling system, A1 coil over shocks. Runs straight and fast. Not perfect by any means, but many smiles to the gallon !

Wanting to add '67 "tall" hood tachometer - all sales/install info says compatible with break point ignition only.
Do I simply wire in an MSD tachometer adapter from the MSD Blaster 2 coil to correct for the signal or am I good to go and wire directly to the existing MSD coil from tachometer ?
MSD makes several adapters - if I need one, is there a recommendation ?
I am not familiar with the tachometer and MSD ignition interface.

Welcome to the ranks of the retireded. Are you using points ignition? Because the MSD 5 was used with points only. MSD 6 and newer were for points, HEI, and other aftermarket electronic ignitions. I had an old HAWK/Cal Custom tach in my '68 hard top and I needed the adapter to make it work. Best to download the MSD instruction manual and see what works with what. I do believe someone makes a hood tach that works with HEI and other ignitions, but points is difficult to work with. Most guys put the Pertronix electronic ignition under the stock cap to look original. But besides it being better than points, works better with MSD and modern tachs. MSD book

Thank you.
Will go throuigh the MSD book.
Great info.

So describe your ignition system. If you are using the Blaster coil only, but still have points, the OEM style points tach will work. When I last had points I used the Mallory Promaster coil, the Mallory Super Condenser, [so big it mounted outside of the cap] and regular GM points. My old tach worked fine. When I started using the GM HEI was when I had problems with the tach.

So I'm using the pertronix d71202, the tachometer works fine but the light doesn't work. I've changed bulbs and checked fuses. Their is a tan, black and black wht stripe. The tan goes thru the firewall to the fuse box(see attached). The black/white stripe is going to the tach spade in the distributor cap. And the black is the ground. Any clue why the light won't work?

Nevermind. Apparently if your using led bulbs it matters which way they go in. Turned it around and it works fine

Brian I forgot what tach you are using. The stock hood tach or a stock dash tach or aftermarket?

And I hate to point this out but this thread does not belong here. Maybe the admins can move it? Hint hint.

It's a stock hood tach. So your saying a question about the hood tach doesn't belong in a hood tach post??

No, it absolutely does. But look at the section heading: [How to: Post Photos, Login, Change Profile, or Find Lost Password]. Just trying to keep things in order. Most sites have a much broader section choice. Some get ridiculous. This site is a bit slim on sections. Electrical is usually a huge section all by itself.

So Brian the stock hood tach works with the Pertronix HEI ignition? I always heard they only worked with a points style ignition.

Ya, works fine

That is strange. A GM HEI will not power the stock hood tach properly. I used to mount a Cal Custom Hawk tach to my steering column on the '68 hard top. It would not work with an HEI nor an MSD unit. I eventually had to buy the MSD converter unit so the tach would work. I wonder what is different with the Pertronix? Do you have the original GM tach filter in place? When I look up the hood tach on Firebird Cental they list the tachs as being for points type ignition only. The filter is also recommended to eliminate spikes and distortion of the signal. It converts the spiked wave to a semi-square wave form. This smooths out the signal so the pointer doesn't bounce around.

Now read this. This DIXCO tach will work with GM points and HEI, but not Pertronix or other aftermarkets ignitions. You need an adapter to modify the voltage. This is from the Fleabay add.: [1960's-1970's Hood Tach Tachometer DIXCO Style 8000 RPM OEM Quality
8 Cylinder Cars Only
Fits 1960s-1970s 8 Cylinder Cars Only
This is a new Dixco tach that was used on several aftermarket applications for super car vehicles like Yenko, Motion, and Big Daddy Garlits. White paint to match. This tach works with factory points and GM HEI distributors, will work with aftermarket ignitions only if you use a module (available through most speed shops).

Tachometers will work with factory GM points or factory HEI ignition. When using an aftermarket ignition system likes MSD, Accel, Patronix, ect. A lot of these systems generates higher output voltage to the tach lead than what a factory GM tach can handle. Factory GM tachs can operate on voltage ranging from 11.2 to 14.7 Most aftermarket ignition systems generate over 18 volts. You will need to buy from the manufacture of your ignition system an adapter to lower the voltage to the GM factory voltage.]

MORE>>>>> You need to install a tach filter between the tach wire and the distributor. The waves that an HEI distributor puts out cannot be properly read by MOST analog factory tachs. I have heard (but never personally seen) of very few instances where a tach worked without any modification. Anytime someone buys a harness from us that is modified for HEI, we typically inform them that they will need to put a tach filter in line on that wire. Accell and Mallory both make a piece, but most any Camaro or Monte Carlo or other HEI vehicles from the 70's/80's will have a tach filter on them if they are equippped with a factory tach. A junk yard trip is possibly in order. They look like a condenser with wires coming out of each end....1 to the coil/distributor cap, the other to the tach wire. They are a plug and play deal. They show up on ebay pretty regularly and can usually be bought for 35-50 bucks. Good luck! MORE>>>>>>>> So, here’s what I’ve learned about OEM tachometers and HEI distributors. Spoke to redline gauges in California about it and he said the tach might work a bit, but will fail from too high amplitude on the tach terminal. It’s designed for a points distributor only and the tach, OEM or OER reproduction will fail if used like this, but they do offer the service to modify it to work properly for all ignition systems. Instrument specialties also offers this service. Hope this helps with our inaccurate and dead OEM tachometers with electronic ignition systems. All this came from the Team Chevelle site. This article is all about the GM HEI but doesn't touch on the tachs. HEI facts

And over on G-bodyforum they are saying you need a filter for a tach to work with any HEI- but then some guys say no problem. Works great. I am totally confused now. I have a couple of original hood tachs and I never used them because of this controversy.

Interesting. I dont know anything about a filter, unless it's internal I don't see one. Give me a week or two and I'll send pics if the wiring and of it working. Broke my wrist in two places Thursday. Having surgery today. So I'm sidelined for a bit. I just assumed it was stock. Possible it's not.

YIKES! How did that happen? Best wishes to you. I hope it all turns out OK. As I got older I had to face the fact that I get hurt easier, and getting better takes longer.

I was cutting a tree down, started to fall, just went to back away and got my foot tangled with the other foot and like a dumbass thought my arm could stop my fall. A plate and 7 screws tells me otherwise, lol. Ya, getting old sucks

OP

I cannot speak to your ignition system. I’m running an MSD programmable ignition box and MSD Pro Billet distributor. To run an aftermarket hood tach I needed an MSD tach adapter. I originally mounted the tach adapter under the dash during the car build only to find out the tach adapter makes an annoying buzzing sound. If you find you need to use one, do yourself a favor and mount outside of the passenger cabin. Willing to share how I hid mine on my ‘68 if interested. Just let me know.

Sorry for the delay to my ignition set-up.

MSD Blaster 2 coil, MSD Pro-Billet Ready-To-Run distributor. (Magnetic trigger, not points.)
No MSD box ..... distributor has that component in it as per the manufacturer.

Ames Performance offers 2 categories of tachometers, Type A and Type B. Type A is taller '67 model. Type B is electrically different, shorter in height, and is for '68-69 Firebirds.

In talking with Ames Performance, the '67 Tach they offer will not run with MSD and they are saying the $100 MSD filter will not fully correct the signal wave problem with using their advertised "Type A" tachometers intended for points. The '67 (taller) tach is offered in "Type A " only.

Ames recommended going with their advertised "Type B" tachometer, '68 model, which I was told will work fine with MSD and does not need the MSD filter module. Red-line RPM (5100,5500) is different than '67 original (5200), and slightly lower profile than '67 original.

Any thoughts out there ?
I'm more interested in a working hood tach, not necessarily the exact original taller 5100 rpm red-line tach offered in '67.
I am poised, ready to drill a hole in my 400 hood .....

Thanks for sharing all that. I would absolutely want a working tach vs a 'correct' tach. I have had so many problems with tachs that I deleted all my MSD stuff. The little tach output terminal on a MSD 6 would only work with my 1977 TA that had a factory gauge/tach. But the convoluted MSD wiring just annoyed the ell out of me. Now I just use the GM HEI and most of my issues are gone. My hood tachs will be another thing so I think experimentation will be in order. I will NOT go back to points just so the tach works! OLY says his 1968 hood tach works fine with his brand new Pertronix HEI so obviously he has it nailed.

Ya, as far as can tell its the original hood tach. It may be a bit before I can show it working. I have the carburetor off rebuilding it, well will rebuild it when I can. Ended up having surgery on my broken wrist. A plate and 7 screws later I'll be on the sideline for a bit.

I have the taller ‘67 tach on my ‘68 because I like the taller tach better. Bought it from The Parts Place. A lot of folks bad mouthed their stuff, but tach has been great for years now. Maybe another option? Does have the glass lens.

I can’t speak to your ignition system. Might want to ask question on MSD forums.

Ok, here is a pic of it working I took today. Again as far as I know it is the factory tach. There is no part number I can see. Haven't tried to take the bottom off to see either though. I will get some pictures of the wiring and how it's hooked up to the pertronix d71202

Ok, from the connector on the tach, the tan wire goes thru the firewall to the bottom spade in the center of the fuse box, one black wire goes to ground, the other to the tach spade on the distributor