hood to fender gap

[cougman67]

Hello all, I have a panel gap question for everyone here. I am working on a 1979 GMC shortbox. I have jobber fenders and doors with the original hood. I am trying to keep the panel gaps close to 3/16" on the doors, fenders and hood. The front of the fenders are at a fixed width and there is no possibility to get it anywhere close to 3/16" gap. It is closer to 1/4" or more, depending on how hard I try. The questions are:

1. What do people do to reduce the gap?
2. What is the original gap on these trucks? From the pictures I see, it is more than what I would expect. This might be normal to account for the hood hinge design. My original pictures show there was a pretty big gap on them but I did not measure it.

Any help would be appreciated.

Patrick

[Matt Man]

Gaps are pretty bad on squarebody trucks to begin with. You close the gap one place and another place opens up. When I put new hinges on my drivers door, the gaps drove me nuts. You just have to find a happy medium. Good luck.

[andrewmp6]

Sometimes you gotta add metal to the edges to close gaps.These are mass production trucks things like gaps can very a lot.

[Keith Seymore]

Factory gap back then was 1/4" +/- 1/8" (sometimes on the same feature).

Gaps today are typically 4mm or 5mm +/- 1mm, depending on vehicle type and location (hood typically more narrow than doors, for example, which require more gap to "swing").

You are correct - the front of the gap is fixed by the width of the rad support, which is unchangeable without major rework. Gaps at the rear were "adjusted" by the addition or removal of shims.

I say "adjusted" because we would typically tape a bunch of shims together and insert those for a period of time, regardless of what the individual truck needed. After a while I would get a call from the supervisor at the end of the line: "SEYMORE!! WHAT IN THE H3LL ARE YOU DOING UP THERE?? ARE YOU EVEN LOOKING AT THESE TRUCKS! FENDERS ARE BUILDING WIDE!! TAKE A SHIM OUT BEFORE I COME UP THERE AND...."etc etc.

So I'd take a shim out and we'd build that way until the next phone call.

He liked me, incidently. That's just the way people talked to each other back then.

K

[cougman67]

I spent the last few hours adjusting the hood and left before I broke something. My father was an old body man and had the knack to make these fit 1/2 decent. I wish he was still around.

[bark]

The worst part is, if you just gap it like factory, everyone will complain on the huge gaps, but if you take time welding in metal and making beautiful finished gaps, most won't even notice...

At the fixed point on the rad cradle, sometimes you can bend the tabs, or massage the fender with some heat and a BFH to get it a bit tighter to the hood at the front.

[Keith Seymore]

Originally Posted by bark

The worst part is, if you just gap it like factory, everyone will complain on the huge gaps, but if you take time welding in metal and making beautiful finished gaps, most won't even notice...

I think the most important thing is to make sure the gap is even along the length of it.

I object more to a "V" gap or an "A" gap then I do the actual width.

K

[cougman67]

I don't know if welding on the hood is a great idea on these hoods. With the gap of these hoods I would hope that lmc would build them a little wider with extra steel on the edges you could file off.

It will wait until next week, Barrett Jackson is on!

Patrick

[barry1982]

I have messed with this same issue..... things get even more tricky using after market parts. Being a bit of a "perfectionist"..... I have used a Die grinder to elongate holes for more adjustment. On more than one occasion, have also relocated the tacked on nuts on the header panel to tighten/expand gaps.

[Cape Codder]

I worked at a GMC dealer body shop from 74 to 80 and we had some customers complain of gaps from the factory. We would move things around as best we could but I don't ever remember one of these trucks with good gaps all around. The frustrating thing was after they had been hit the customers would be looking for poor fit, and gaps that were not noticed when new were then scrutinized.