jonesy wrote:

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I am helping a friend restore a 71 GTO, he bought an original Hood Tach and a new rear wing and wants me to install them. My prblem is that I would like to get the placement correct the first time, does anyone out there know were I can find measurements or templates to help me do this. I have searched Google and GM catalogues and cannot find anything. This guy has had this car for over 30 years and I don't want to screw it up.

Thanks Les

Page 1 of 2 1 2 > 07-27-2008, 02:04 PM   #8 (permalink) Eric Animal Join Date: Oct 2007 Location: Long Island NY Posts: 350 My Photos: (0) Matt, If you measure out 9 inches from the rear of the hood (cowl), then measure out 10 inches from the edge of the hood (driver's side, at fender), the intersection of these 2 points will be the center of where to drill a 3-3/4 inch diameter hole. Next. set the tach into the hole and mark the location for the 2 stud holes. The tach should sit into the holes with the front edge touching the hood 4-5/8 inches from the hood edge (cowl)....According to my calculations this WILL involve cutting into the brace under the hood skin. This will make more work, but a better job as the tach will have more support........I haven't installed mine yet, as I have the original hood on my car....there isn't enough JIM BEAM inthe house right now to give me the b-lls to take a 3-3/4" hole saw to the hood I hope this helps......put masking tape on the hood first and lay the job out......Measure 25 times then cut once...................Eric   07-27-2008, 02:19 PM   #10 (permalink) My Custom S Join Date: Jul 2008 Location: Waxhaw, NC Posts: 8 My Photos: (0) Mr. Animal, Thank you for the dimensions, that is what I was looking for and it appears to agree with what I have seen in the field as far as cutting into the rear underhood bracing is concerned. Since this is NOT a concourse trailer queen restoration underway, I will start with the dimensions given and then adjust from there. This particular tach has (4) mounting studs, so I'm not too concerned about utilizing part of the underhood bracing for additional support. If it means sliding the tach away from the windshield an additional inch or so to avoid the bracing, I may just do that. At the end of the day it has to sit dead center in my line of vision and not so far that I need to prop a magnifying glass on the dash!! This is an NOS hood but I've already had a visectomy so I'm ready to start cutting! I'll take a few pictures and let you know where I ended up and perhaps that will help you with your project. Hopefully my hole saw will do a slightly better job than Rukee's tool of choice, however before it's over with I may have well used one! Thanks again for the info and support. I'll report back later. Matt   Page 1 of 2 1 2 >

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455gto wrote:

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jonesy wrote:

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Thanks Guys, I appreciate all the help, I have ordered a GTO restoration book and I have copied the dimensions given here. I also think that there will be a lot of Rum involved before drilling the first large hole in an original hood that only received it's second coat of paint a couple of years ago. My issue with the rear spoiler is that it is not a repo unit with all the new hardware and templates but an original that I found on ebay. My brother and I are planning on building a 66-67 GTO for him as soon as we can find a ( builder ). I can see that this site will be lots of help.

Thanks Les

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I drilled my rear wing. If you look at the back of the trunk. The two rear holes go just before the hump for the trunk lock. You'll see that it fits in the two triangular pieces where the trunk is the thinest. The front bolts are just at 2 o'clock beside the 3" circles and about 1/2" away from the humps on either side. I drilled from the back side with a pilot  hole and then the other 3 were measured from the top and drilled from the top.

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 Damn Kim that looks good in there !!!

dualquadpete wrote:

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Old posting from 2009 wonder how he made out?????

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 I was wondering the same thing.. :>)