63-72 Chevy & GMC C10 Rear Frame Crossmember (Bolt-On)

63-72 Rear Frame Crossmember - # 120-5600

Our bolt-in rear frame crossmember is designed specifically for 1963-1972 C10 chassis to restore structural integrity after a backhalf or rear frame modification.

When lowering a truck, the factory rear frame structure is often cut or removed, leaving the frame rails unsupported. This crossmember ties the rear of the frame back together, keeping the rails square, rigid, and capable of handling suspension and drivetrain loads without flex or long-term fatigue.

Unlike weld-only options, this crossmember features sliding inlays that insert into the frame rails, providing a strong connection and precise alignment before bolting everything together. The result is a clean install with excellent strength and repeatable fitment.

Key Features & Benefits

• Designed specifically for 1963-1972 C10 frames

• Restores strength after backhalf or notch modifications

• Prevents rear frame rail flex, twist, & cracking

• Bolt-in design with internal frame inlays for added support
  

Design & Construction

• ASTM A1011 hot-rolled steel 

• Precision-cut for consistent fitment

• Internal frame inlays slide into the frame rails for added strength
  

Dimensions & Specs

• Weight: 12 lbs

• Overall Length: 33 inches

• Frame Rail Inlays:

  • Height: 3.5 inches

  • Depth: 2 inches

• Crossmember Face:

  • Height: 4 inches

  • Depth: approx. 1.5–2.0 inches

Vehicle Fitment

• 1963-1972 Chevy & GMC C10 Trucks
  

Installation Notes

• Inlays slide into frame rails to align with OEM bed mount holes. (Longer bolts may be required for bed variant)

• On rare occasions, since the stock frame rails have nothing supporting the rear, they tend to bow in over time, narrowing close to an inch; this will require spreading the frame rails via porta power or another accessible tool.

• Welding not required (can be welded if desired)

Installation Notes

• (1) Rear Frame Crossmember with Logo

• (2) 3/8" x 1.25" Bolts
  

• (4) 3/8" Washers

• (2) 3/8 Nylock Nuts

• (2) 1/2" x 1.25 Bolts

• (4) 1/2" Washers

• (2) 1/2" Nylock Nuts

California Proposition 65 Warning

Cancer and Reproductive Harm – www.p65warnings.ca.gov

Questions? Contact Us

(480) 940 1806 – Local
1 (877) 951-1890 – Toll Free

At GSI Machine & Fabrication, we offer a one-year warranty on all manufactured parts, covering defects upon inspection. However, we are not liable for personal or property damages resulting from misuse of our products. Note that warranties for non-manufactured parts, such as shocks or ball joints, must be handled directly with the part’s manufacturer.

Orders may be canceled before shipment, except for special-order and custom items, such as chassis products and air ride suspension. Refunds for eligible returned items will exclude shipping costs and may incur additional fees. For cancellations or issues with orders, contact our customer support at 1 (877) 951-1890 or sales@gsimfab.com.

Customers are responsible for all customs fees, duties, and taxes on international orders. Once your package is shipped, we are not liable for damage, theft, or loss during transit. Please inspect your delivery promptly and report any issues within 48 hours. For international shipments, local policies may cause delays, and additional documentation may be required. Always ensure shipping details are accurate to avoid additional costs.