Hanging a reproduction fender so the gaps look factory

A reproduction front fender will bolt on. Whether it looks right afterwards is a separate question, and the answer is decided by how you approach the bolts rather than by the quality of the panel.

01Understand what the bolt holes are for

The mounting holes are slotted. That is deliberate. The factory needed adjustment range on the assembly line and so do you. Which means the panel does not have a single correct position — it has a range, and your job is to find the point in that range where three gaps are simultaneously acceptable: fender-to-door, fender-to-hood, and fender-to-the-front-end structure. You cannot optimise these one at a time. Moving the fender to fix the door gap changes the hood gap. This is why it takes several iterations and why tightening everything down on the first attempt wastes the afternoon.

02Order matters

Work back to front: 1. The door first. The door is the reference because it is hung on hinges bolted to the cowl, which is structure. Get the door gap right against the rear of the door aperture and the rocker, and leave it alone. If the door is not right, nothing forward of it can be. 2. Then the fender, aligned to the door. 3. Then the hood, aligned to both fenders. 4. Then the front valance, grille and bumper, which have the most adjustment and the least visual importance. Anyone who fits the fender first and then tries to make the door match is going to be there a long time.

03Check the cab mounts before you start

On a truck, sagging cab mount bushings change every gap forward of the doors. They are rubber, they are the original ones, and they have been compressed for fifty years. If the bushings are tired, replace them before hanging panels. Otherwise you will align everything beautifully to a cab that is sitting 10 mm low at one corner, and then it will all move when somebody eventually replaces them.

04Fitting

Get the fender on with a helper — they are awkward and easy to scratch. Blankets over the door and the cowl. Every bolt finger tight only. Not snug. Finger tight, so the panel can still be moved by hand and will hold position while you stand back and look. Then adjust, using the slots. Shims where the manufacturer used shims — usually at the cowl and along the inner structure. Reproduction panels frequently need more shimming than original ones did, because the stamping is a little different. Check by eye from several feet away, not from up close. Panel gaps are judged at conversational distance in daylight, and a gap that looks fine with your nose against it can look obviously wrong from ten feet.

05What "right" looks like

• Even width down the whole length of the gap. A gap that tapers reads as wrong even to people who could not tell you why.
• Flush surfaces. Run a hand across the joint with your eyes shut. A step you can feel is a step you will see once it is painted, and paint exaggerates it rather than hiding it.
• The body line continues. Where a character line crosses from fender to door it must line up. This is the one people notice most, and it is worth sacrificing a little gap evenness to get it right.

Factory gaps on these vehicles were not tight by modern standards. Roughly 4–6 mm was normal, and it varied. Chasing a 3 mm gap all round produces something that looks like a modern car, which is not the same as looking correct — and it leaves nothing for the panel to move into on a hot day.

06Then torque it down, and check again

Tighten progressively, working around the panel rather than doing one area completely. Then check every gap again, because tightening moves things. Open and shut the door twenty times. Open and shut the hood. Bounce the front suspension. Then look again. Things settle, and it is better to find that now.

07Before paint

Do the final alignment before paint, then mark the position of every bolt with a paint pen so it can be reassembled to the same spot. Nothing is more discouraging than a perfect fit-up, a beautiful paint job, and a panel that will not go back where it was. And treat the inside of the panel while you have access — the inner surface is where it will rot from, and it will never be this easy to reach again.