[FBird69]

I have a factory hood tach, but since I went to electronic ignition, the tach has not been accurate (off 10-30% depending on RPMs). I initially tried Pertronix and was disappointed with the inaccurate RPM reading so I next tried Crane XR-i which also produced inaccurate RPM results. Which brings me to my question, which aftermarket hood tach is the best for 1969 FB? I want one that:

1) looks factory original
2) does not require any hood modification from factory installed tach
3) works accurately with aftermarket electronic ignition (possibly an adjustment feature?)

Is there such a thing that exists which will allow RPM adjustment if placed on the NEG wire in between the coil and tach?

I did a search of previous posts back a year or two, and some suggested the The Parts Place, some others Ames and YearOne. THANKS for your help!

[Tim john]

Reach out to Randy Watson, he builds the best reproduction hood tachs or he can modernize your original. PM sent to you with his contact information.

Tim john---

[DOC]

I put one of the ones packaged from OER. It is same as my external tach on my timing light that I can hook up. I have only tested to 3500 RPMs with the other tach side by side and they are identical.

Added a red LED instead of the regular bulbs.

[north]

The two versions that everyone sells are both wrong looking in the case. I forget which is which but the "cheaper" one has the wrong shape where it meets the hood around the face, it doesn't have the bottom flare right and the leading edge that surrounds the face bezel is to thin.
The more expensive one is just as wrong, too fat looking and the bezel is too thick and rounded.

The funny thing is the original hoodtach repros from back 20 plus years ago which had that awful plastic face that let the light through had very nice cases and bezels.

The first picture is of the factory original tach on my GTO and the second is the "better" quality repro on my Firebird. As you can see the bezel is completely wrong and the case around the bezel is much too fat looking.

Why in the hell can't they just get it right? Not rocket science!

[DOC]

hard to tell, but my OER one looks like your 1st pic.

[silverbullet07]

This is one I got from The Parts Place about 3-4 years ago. I don't see it on their site now but it may be the same as OER.
Works well with pentronics. I have a gasket under mine so you will see that in this shot.

['ol Pinion head]

Originally Posted by Tim john

Reach out to Randy Watson, he builds the best reproduction hood tachs or he can modernize your original. PM sent to you with his contact information.

Tim john---

X2...

[Peter Serio]

Part of the way that the new ones are made I think had to do with the sealing surfaces. The way the front piece and the tray mate with the top half around the lens is critical in keeping water out.

The older GM tachs; I can't ever remember seeing one that hadn't gotten moisture inside of it at some point or another.

[north]

Here is the other version sold by Ames, as you can see the case doesn't flare out at the bottom

[north]

That green repro on my Firebird has never gotten wet ever (I remove it when I wash the car) and it still acts up, sometimes it jumps all over the place, other times it just dies and the lens is dirty looking because the guy who built it used too much silicone inside and the bulb melted it, filling the inside with a smoky film.

I added a Goodrich because the car came without one and I didn't want to pony up the big coin for factory stacked gauges and a dash tach. I regret it now.

[FBird69]

THANKS for all the input, much appreciated! I'm going to do some more testing on my factory tach to see if I can narrow down the issue a bit more as I would like to keep the original if at all possible.

[rctach]

One thread below states why can't they just get it right. Quotes for injection molds from around 15 years ago were, $23,000 for shell, $18,000 for base, $12,000 for bezel. Then there was the metal face plate, RPM tab, metal ring behind the glass that requires metal stamping molds or plastic molds, meter movement, circuit board, cut glass lens and harnesses. All very very costly so i made do with much cheaper vacuum formed molds. However with today's 3D scanning technology, it has made Injection molds much more affordable (still costly though). I started with NOS Hood Tach Parts had them 3D scanned, Printed with a 3D printer to prove the part dimensions were correct. Then the data from the scan was converted to data that the injection molds were made from on a Cad machine. The bezel and base plate worked out with few touch ups to the data and only a couple test 3D printed parts made, they couldn't get the shell correct. It took over 2 years for them to get it correct, they made several injection molds that i rejected parts out of and were scrapped before they got it right. The Hood tach finished product is the sum of the parts used. Here are some pictures of my latest attempt to get it right. The pictures are side by side to original parts. The movement used is an air core movement, the circuit board is designed by me and made specifically for this hood tach, glass lens, correct pointer shape, correct redline colors, correct Part numbers on the bottom of the tach. I build and calibrate each tach myself so if there is ever a problem you come back to the person that designed and built it.

[rctach]

One more pic for previous post.

[SD455DJ]

Randy, Can we buy hood tachs directly from you? If so, I would love to get one from you.

Dennis

[rctach]

Yes Just PM me.

[tekheavy]

Got this from The Parts Place a couple of weeks ago, Installed it this weekend. Very pleased with quality.

[RAIVJUDGE]

An original tach

[92GTA]

Originally Posted by RAIVJUDGE

An original tach

Wow, ThePartsPlace tach is super close!

I installed mine a few months ago and couldn't be happier.

[Ram4king]

Originally Posted by 92GTA

Wow, ThePartsPlace tach is super close!

I installed mine a few months ago and couldn't be happier.

No it's not when you put them side by side. Mike bought that tach from me from my collection. I still have 10 more.

[SD455DJ]

I just ordered one from Randy and can't wait to get it. I'll compare it to the old beat-up factory HT that came on the GT-37. Randy's look to be more faithful than anything else available.

Dennis