Hole in the hood or hole in the head?
 

I'm curious as to how the 68/69 crew feels about cutting that big hole in a good hood for a hood tach.
Now, I know that the standard answer that always comes back is- "It's your car, do what you like" and there's nothing wrong with that answer except that that is not the question. How do you feel about it?

It’ll make your GTO even cooler. Cut the hole!

I never once have regretted it!

My in-dash tach took a dump quite a few years ago and I really miss having a tachometer in just about any kind of car, but especially this one. Even though I wasn't actively shopping for one I ran across a pretty good deal on a hood-tach and bought it. Then the doubt started creeping in....
I just finished wiring it under the hood to see if it worked and it's perfect. Then I come back here and see these replies and I'm getting a little stoked... I guess a hole saw is in my future!

Greg Reid my only input to this is...... post up some pics when she's done !!

She'll be even lighter!

Haha, will do HO LEMANS!
The biggest challenge for me will be getting it painted without too much orange peel. Being a relatively small job I'm considering using an airbrush. Gotta play around with some test panels.

Use a punch out tool easier and cleaner

I've used them before but don't have one. I'll bet a good three and a half inch one is pretty expensive. Also, the placement of the hole has it coming through a fair bit of the bracing. Will a punch out tool stay straight going through the multiple layers on one side of the hole only?

Just get the Hood Tach 1st, then cut the hood. And perhaps a Dash Clock. You are gonna want that.

Well, I have the hood tach already and yeah, at some point I'll replace the blown dash tach with a clock. I'm in no hurry to pull the instrument panel though.
I wired the underhood harness today so l'm committed to doing it. When I get it painted to my satisfaction I'll cut the hole.

I used to be able to remove/swap the Dash Clock ( or Dash Tach ) by using a 1/4" nut Driver, without removing any Dash stuff.

Certainly remove the Lower AC vent system if it were there.

My last effort with installing the Dash Tach was tedious to do such. Think i removed DashPad to properly R&R the 2 upper 1/4" screws.

Do it. Too cool not to.

Go for it…no regrets adding one to mine. Here’s a few pics of my install. Mine wasn’t as nerve racking since my hood still needs painting.

Thanks kk68. Those pics are helpful. I'm using the template provided with the tach and it puts the center of the hole 13" from the back edge of the hood. 3/8" closer than yours and I guess that's close enough but it looks to me that you barely had to touch that hood bracing when you cut your hole. Mine appears to be taking quite a lot more from just eyeballing it. That's a concern because I don't want to have to cut through any more of that bracing than I have to.
In fact, as close as I can tell, the front edge of that bracing is going to wind up almost at the center line of my 3.75" hole! Right about where the threaded studs are. I think I need to move it up 3/8 to 1/2" to be closer to where you are.
Also, that 2* offset isn't mentioned. If anything, looking at my pattern it seems to be offset about the same amount but in the opposite direction.
https://uploads.tapatalk-cdn.com/202...6fc2463901.jpg

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I did a lot of research on locating the proper size and spot for the hole and settled on the location from prior post. This is an old photo I found that showed the factory location from the underside of the hood with minimal cut into the bracing…very close to where I ended up.

The Hood tach is worth it and just make sure you use the correct Template and put the hole in the correct place.

I'm comfortable with the location now... I moved my pattern forward about half an inch and looked at it carefully from the side with one of those little antenna magnets stuck to the front edge of the brace. That gave me a visual marker from the side where I could see my pattern and the little antenna hanging down from the bottom of the hood at the same time.
I think it's going to wind up in just about the same place as that photo you just posted.
I'm definitely not cutting anything until I can get the paint right. I don't want it to look like an add-on, but like it was painted with the car.

I've always wanted to add a tach to the hood of my 71 LeMans, but cringe every time I look at my perfect original hood. A guy up the street did it to his 72 and it looks great. I guess a good look under his hood to see what he cut into is my next project. Anyone else do theirs? GREAT THREAD!!