[lintmann]

Hey guys, Happy New Year, I wish everyone a healthy and prosperous new year!

I'm thinking I have an issue with the trunk gaps on my 70 GTO but before I go down that rabbit hole I'd like to know if anyone would happen to know what the tolerances were for production cars. I looked in my assembly manual and can't find anything. I don't have a Fisher Body Manual but found a PDF version for 1971 and can't find any specs there either.

My concern is because the trunk opening isn't square, it's a slight parallelogram(see attached pic). The gap between the trunk and trunk filler panel is okay as is the flushness between them. Also the general flushness of the trunk lid to quarter panels also looks good. It's the gap between the trunk lid sides and quarter panels that is noticeable. I've compared the gaps to other A bodies of the era and they mostly have much better looking gaps...

Now assuming that my trunk gap is off, I was wondering if I could get some opinions on how to best "square up" my trunk opening. The car has never been hit but due to rust, the trunk filler, drivers full quarter panel and the rear tail panel have all been replaced with panels from a donor car. I have also tried a different trunk lid with the same results so that should rule out a bad trunk lid.

Any thoughts on what those gaps should be and how to square things up is appreciated.

[Paul E]

Yours fit much better than mine. I had larger gaps on both sides and stitch welded with MIG 3/32 TIG rod on both sides to take up the gap. Kept a hard edge. Was easy to do and fill and really did look nice. Likely yours is not that bad.


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[400 4spd.]

I suspect the key is the driver's side quarter replacement. If you had not described the past repairs I would have asked if it shows signs of being hit in the left rear.
If the gap along the forward edge is even all the way across, you might need a slight sideways tug on the left rear corner to square the body up with the lid.

[Paul E]

Originally Posted by 400 4spd.

I suspect the key is the driver's side quarter replacement. If you had not described the past repairs I would have asked if it shows signs of being hit in the left rear.
If the gap along the forward edge is even all the way across, you might need a slight sideways tug on the left rear corner to square the body up with the lid.

Good advise and solution

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[MUSLCAH]

Block of wood and a hammer

[lintmann]

Thanks guys, I was thinking a "slight tug" would do it too but I'm just not sure on how to go about it.

I know the pic doesn't give it justice but the body and paint is done(I did a light dusting of cheap white enamel to show the gaps) and would prefer to not have to do much paint work as all it needs now is a light wet sand and polish. For this reason I'd prefer to not take it to a body shop to be pulled into shape.

So with that in mind what would be the best way to "tug" it square. My initial plan was to separate the tail panel from the trunk floor where they join under the bumper lip. That should make it easier to move and square things up but if there is a better way that you guys could recommend please let me know.

Oh and does anyone have any info on what the gap tolerance should be?

[MUSLCAH]

I have no clue why people paint cars......then try to fix the gaps after. But with out removing that scab.....I’d live with it now . It’s not hitting or rubbing right ? It’s all these dang car Resto shows that has shined a bright light on “GAPS “ .....These cars didn’t “fit” from the factory....now every one has to have a car that fits like a BMW with today’s computers and tight tolerance. If it was a Concors car...those gaps would have been addressed ....before paint. Just enjoy it.

[lintmann]

Thanks muslcar but the person that painted the car isn't trying to fix the gaps, I am. I didn't realize the gaps looked that bad when I picked the car up years ago and even if I did it would likely have been a moot point because the situation was that I had to get the car home that same day.

I'm obviously not looking for Resto Show, BMW or concourse gaps which should be apparent when I asked if anyone had specs for what the factory allowed. If these gaps are within regular production build tolerance then they will stay, if they are not then I will see to it that they are put back to within these tolerances.

Thanks for your thought but what I am really asking for is confirmation that the gaps are in or out of spec or constructive solutions to set these gaps back to those factory specs.

[dataway]

Have someone climb inside the trunk with a wrench and a light ... loosen the bolts, you adjust from the outside, then tell them to tighten up the bolts

[TAKerry]

It looks to me like its out of square in a bad way, meaning that tweaking from one corner to the other will only make it worse not better (being that it is out of square parallel).
If this were my car I would call it water under the bridge. I have seen far worse gaps, especially from the factory. I would think the best way to correct at this point would be too invasive. Welding an edge on the trunk lid is one example and pulling a panel loose is another, but you need to ask yourself if it is going to bother you that much in the long run.

[1965gp]

This is a good point- especially considering this is a trunk gap that you see from a distance and not a door gap you see every time you get in the car. Also being that it is a dark color I would expect that to help as well.

If you are going to fix it I would be inclined to modify the trunk lid- not the quarters. Start pushing and pulling on the quarters and you may end up with bigger problems.

I like the idea of having someone in the trunk. You could use plastic pry bars (like you use on interior pieces) to pry it one way or another. May need to loosen the latch as well

Curious- did you say you painted white paint on the car to show the gaps? Effective but seems like it would be a mess to clean up?

[Paul E]

Always can try and loosen the rear frame mounts and just try and pry it over a little. If it moves a fraction that is likely all you would need and only take a little effort and time. Keep it simple ar else it could be a much larger project. My trunk was wide evenly on both sides that is why I welded on it to make it correct. the gaps were even. I stitch the top completely and did stiches on the bottom for less heat and chance of warping. I then filled with all metal on the bottom and it looks very nice.

[3goats]

Hey Lintmann
I believe in my 69 assembly manual I read somewhere? the factory would not accept gaps over 1/4". That's why some came from factory better than others but nowadays every one has to have perfect 3/16"gaps or somethings wrong. If it was mine I would split the difference and not have to repaint it.That is the reason I do all my own panel fitting. Been burned before .
Good luck.

[MUSLCAH]

I looked in my Fisher 1967 book....A Body Pontiac were 1/8 inch gaps.....Chevy Olds Buick we’re wider... don’t know if that changed for 1970.

[MUSLCAH]

Originally Posted by Paul E

Always can try and loosen the rear frame mounts and just try and pry it over a little. If it moves a fraction that is likely all you would need and only take a little effort and time. Keep it simple ar else it could be a much larger project. My trunk was wide evenly on both sides that is why I welded on it to make it correct. the gaps were even. I stitch the top completely and did stiches on the bottom for less heat and chance of warping. I then filled with all metal on the bottom and it looks very nice.

Hot dam...that’s a lot of work. In my 43 +years of doing Paint and body work...collision work....I can honestly say, I’ve Nevah gone to that extent before on making a panel fit. But glad it worked out for yah.

[Paul E]

Really was done in less than one night. Only had to grind the top of the weld as the edge was made straight band had the radius from the TIG rod I welded on. Note this also works for doors.


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