Square-body crew cab dually rear fender trim: what it is and where owners look for it

Owners of 1973-1987 Chevrolet and GMC crew cab dually trucks, the "square bodies", often find that the trim around the rear fenders is missing or damaged and that nobody seems to sell it. This page describes what the part is, why it is hard to find, and how to work out what your truck should have. There is little reputable documentation for this specific piece, so the page is short and says where information runs out.

In this guide

What is the part?

A thread on the GM Square Body forum from an owner of a 1976 C30 crew cab dually asked for "the body side molding pieces that go in front and rear of the rear fenders". A moderator clarified, using photos, that the piece is the fender trim that connects the upper and lower trim strips on the dually's rear fenders.¹ In other words, it is not the long body-side molding along the doors and cab but the short connecting pieces at the dually fender.

Why it is hard to find

In that thread, long-time owners said it had been very hard to find these pieces: one moderator said they had looked for a set for more than ten years, another had looked on and off for three years without luck, and one said they had seen only a couple of decent sets in about a decade.¹ The thread did not name a part number or an aftermarket source. Crew cab dually trucks were a small share of production: Wikipedia notes the crew cab arrived in the mid-1970s in this generation and the one-ton dually was only offered with an 8-foot bed.²

Which trim does your truck have?

Trim varied with model year and trim level. For Chevrolet, Wikipedia lists Custom, Custom Deluxe, Cheyenne and Cheyenne Super in 1973, with Scottsdale and Silverado added in 1975, and for GMC an all-Sierra range by 1975 with Sierra, Sierra Grande, High Sierra and Sierra Classic.² The upper-and-lower trim arrangement a truck carried depended on its level and year, so:

1. Look at the truck itself for mounting holes, clip holes or ghost marks where trim used to sit.
2. Find a matching-year, matching-trim truck, or a good photo of one, and compare.
3. Confirm your truck's exact model year and trim level from its documentation (cowl tag, original paperwork), then ask owners of the same year and level what theirs carries.
4. Model year matters, because trim names and arrangements changed over the generation.²

What is available?

Reproduction parts exist for nearby trim but not necessarily for this piece:

• Brothers Trucks sells reproduction aluminium moldings for 1973-1980 Chevrolet and GMC trucks, including cab, wheel-opening and lower rear body moldings.³ That page could not be opened, but these are not described as dually-fender connectors, so check with the vendor directly before buying.
• USA-1 Industries sells reproduction dually rear fender marker lights for 1973-1991, with a version with aluminium trim rings and one without.⁴ Those are lights, not the connecting trim.
• Original pieces turn up in truck forums, salvage yards and swap meets, or via owners who are converting dually trucks to other layouts, as one forum member offered in the thread.¹

Realistic approaches include a condition search for original pieces, a custom fabrication from an existing piece if you can borrow one, and asking restoration specialists whether anyone can produce them. Check live listings and ask forums; availability changes.

Before you buy any trim

• Confirm the piece is for a dually fender, left or right.
• Compare to photos of a correct truck, and confirm clip or stud arrangement.
• Check the finish and the aluminium for dents or corrosion, because bent trim does not straighten well.
• Test-fit before painting or final installation.

Write a wanted ad that identifies the exact dually molding

Searches for "square body trim" are broad enough to bring back door strips, wheel-arch moldings and marker lights. Make your enquiry specific: model year, Chevrolet or GMC, crew cab dually, the trim location, the side required and whether you need the front or rear connector at the fender. Add both "molding" and "moulding" when searching different regions.

Include a photograph with the missing location marked, a photograph of a surviving matching piece if you have one, and a ruler alongside it. Ask respondents to show the reverse side of their part as well as its face. The curve, attachment arrangement and finish matter as much as the visible outline.

A useful wanted-ad opening is: "Looking for the short rear-fender trim connector shown in the attached photo, for a [year] [Chevrolet/GMC] crew cab dually. Need [location/side]; please send front and rear photos, dimensions and details of any damaged mounting points."

Should I buy a whole donor set for one missing piece?

Ask for an itemised description first. A set may contain ordinary body strips but omit the scarce connector you need. If it includes your piece, consider whether the spare parts justify the extra purchase and shipping cost.

Can a restoration shop reproduce it?

That is an enquiry worth making when no original is available. Provide a real sample or detailed measurements, ask for a separate fabrication and finishing quote, and distinguish a custom reproduction from an original part when documenting the restoration.

Sources and further reading

1. In Need of Body Side Molding for 76 Crew Cab Dually Rear Fenders, GM Square Body forum: owner opinion, attributed.
2. Chevrolet C/K (third generation), Wikipedia: generation history and trim levels.
3. Brothers Trucks Upper/Lower Cab Molding 73-80, CJ Pony Parts: vendor catalogue entry.
4. Dually Truck Rear Fender Marker Light Kit, USA-1 Industries: vendor listing.