Diversified Design and Fabrication 91 GM Truck Front Bumper Installation Guide

: August 31, 2024
: Diversified Design and Fabrication

Table of Contents

91 GM Truck Front Bumper
Specifications:
Product Usage Instructions:
1. Bumper Build Procedures
2. Light Bracket Build Procedures

91 GM Truck Front Bumper

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Specifications:

Material: 3/16 mild steel (7 gauge) for bumper parts, 10 gauge
mild steel for end caps
Tools Required: Welder, Angle Grinder, Flap Disc, Cut-off
wheel, 19mm wrench/socket, 12mm wrench/socket, 3/8 Ratchet, 1/4
Ratchet
Hardware: Various bolts, washers, nuts
Torque Specs: 1/2-13 x 1-1/4 – 80 lb/ft, 1/4-20 x 7/8 – 9
lb/ft

Product Usage Instructions:

1. Bumper Build Procedures

1. Inspection

Inspect all parts to ensure everything is included and in good
condition.

2. Welding Prep

Prepare surfaces for welding by removing mill scale. Areas to
prep include:

Bottom and top wings of bumper gussets
Areas where bumper gussets will be welded to the bumper
center
Areas where nuts are welded to the bumper center
(optional)
All bumper bend relief lines front and rear
Bumper end caps for driver and passenger side
Bumper light mounts and welding areas

3. Welding

Follow welding instructions to assemble the bumper components
securely.

4. Finish

Apply a protective finish to prevent rust. Options include
primer, CARC tan substitute, or powder coating.

2. Light Bracket Build Procedures

1. Weld

Weld the light bracket with a tab-and-slot design at a 90-degree
angle. Use inch stitch welds for secure attachment.

2. Finish

Apply a protective finish to the light bracket as per your
preference to prevent rust.

Frequently Asked Questions (FAQ):

A: A combination of grey primer and CARC tan substitute is
recommended. Powder coating is also a suitable option.

Q: What tools are required for assembly?

A: You will need a welder capable of welding up to 3/16 mild
steel, an angle grinder, flap disc, cut-off wheel, various
wrenches/sockets, and ratchets.

Q: How should I prepare surfaces for welding?

A: Remove mill scale from designated areas such as bumper
gussets, nut welding points, bumper bend relief lines, end caps,
and light mounts before welding.

Q: Where can I provide feedback or suggestions?

A: You can share your feedback, pictures, videos, testimonials,
or comments with the manufacturer via email at
info@diversifieddesignandfabrication.com.

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Marcus Woodard, Owner Fort Worth, TX ddandfab.com info@diversifieddesignandfabrication.com

DD Fab CUCV Front Bumper Assembly Instructions
(’81 ’87 (’91) GM Trucks)
Required Tools
Welder capable of welding up to 3/16″ mild steel Angle Grinder Flap Disc Cut- off wheel 19mm wrench/socket 12mm wrench/socket 3/8″ Ratchet 1/4″ Ratchet

Parts List

Part

Qty

Description

Bumper

1

3/16″ mild steel (7

(Center)

gauge)

Bumper

2

Gussets

3/16″ mild steel (7 gauge)

1

Bumper (Driver)

Marcus Woodard, Owner Fort Worth, TX ddandfab.com info@diversifieddesignandfabrication.com

1

10 gauge mild steel

Bumper

1

(Driver

Corner)

Bumper

1

(Driver End

Cap)

10 gauge mild steel 10 gauge mild steel

Bumper

1

(Passenger)

10 gauge mild steel

Bumper

1

(Passenger

Corner)

10 gauge mild steel

2

Bumper (Passenger End Cap)

Marcus Woodard, Owner Fort Worth, TX ddandfab.com info@diversifieddesignandfabrication.com

1

10 gauge mild steel

Light Mount x2

11 gauge mild steel

Light Bracket x2 (Optional) 11 gauge mild steel and tab

Part 1/2″-13 hex bolt, 2″ 1/2″-13 hex bolt, 1.25″ 1/2″ washer 1/2″ hex nut 1/2″-13 weld nut 1/4″-20 hex bolt, 7/8″ 1/4″ washer 1/4″ lock washer 1/4″-20 hex nut 1/4″ round bar

Hardware
Qty 8 6 6 8 6 4 4 4 4 6ft

Torque Specs
1/2″-13 x 1-1/4″ 80 lb/ft
1/4″-20 x 7/8″ 9 lb/ft

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Bumper build procedures 1 Inspection
2 Welding Prep

Marcus Woodard, Owner Fort Worth, TX ddandfab.com info@diversifieddesignandfabrication.com
The bumper bolts to the truck in 8 spots. 2 on each inner bumper bracket, and 2 on each outer bumper bracket. The mounting holes are designed as slots to allow for some side-to-side adjustment to allow for easy fitment. Before welding your bumper, assemble the outer wings to the center section using the supplied 1/2″ bolts and nuts. Then bolt the bumper to the truck. At this point there should be not fitment issues if you have original bumper brackets. Aftermarket outer bumper brackets might require you to drill new holes on the bottom of the bumper.
Now it is time to prep all surfaces to weld. Remove mill scale to allow for proper weld penetration. Areas to prep are listed below:
1. Bottom and top wings of 2x bumper gussets.
2. Areas where bumper gussets will be welded to the bumper center.
3. Areas where nuts are welded to the bumper center (x6). This step is optional but recommended.
4. All bumper bend relief lines front and rear. The supplied 1/4″ round bar should be cut to length in order to be stitch welded to the back of the bend lines. This helps prevent warping and makes welding the bend lines easier.
5. Bumper end caps for driver and passenger side.
6. Bumper light mounts and area on bumper where they will be welded.

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Marcus Woodard, Owner Fort Worth, TX ddandfab.com info@diversifieddesignandfabrication.com
3 Weld
Normal weld procedures apply. Take special care to ensure not to apply too much heat. The outer wings have an approximate 4 degree bend from center to outer and have the potential to change if too much heat is applied. Make sure that the outer pieces to the bumper are lined up with the top of the bumper. I recommend welding around 25% of the bumper at a time and give the bumper about 15 minutes to cool. There is approximately 175″ of welding. After welding is complete it is time to smooth the bumper. I used a regular flap wheel. You can also take it a step further and apply bondo and sand to a smooth finish.
5 Finish
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Marcus Woodard, Owner Fort Worth, TX ddandfab.com info@diversifieddesignandfabrication.com
Now it is time to apply your finish of choice to protect from rust. In this photo, I used 2 coats of grey primer, and two coats of CARC tan (686) substitute. Powder Coating would also be a great option.

Light Bracket Build Procedures

1 Weld

The light bracket is very simple to weld. It has a taband-slot design and should be welded at 90 degrees. An inch stitch weld on the end of the tab is sufficient.

2 Finish

Now it is time to apply your finish of choice to protect from rust. I used 2 coats of grey primer, and two coats of CARC tan (686) substitute. Powder Coating would also be a great option.

Feedback
I look forward to hearing your feedback. Please send your pictures, video, testimonials, comment, or suggestions to info@diversifieddesignandfabrication.com. I would love to feature your pictures on the website and social media. I also welcome any feedback to make product improvements. Thank you for your business!
-Marcus Woodard
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