1978-1983 G-Body Crossmember- 4L80 with frame extension | RCG-4L80K

See the G Force Crossmember Overview for more info.

On some installations, it is necessary to remove the catalytic converter heat shield from the passenger side floor pan.

For all 78-88 G body crossmembers the passenger side hump is the taller of the two.

This generation of vehicle is prone to body bushing compression, even with some southern vehicles. If the floor pan is too close to allow installation, it may be necessary to replace the body bushings. Some customers have reported that with instances where there is slight interference they have been able to gently lift the floor pan with the assistance of a floor jack and a wood cushion to create enough clearance for installation.

This crossmember is installed so that the exhaust clearance humps are closed on the top and open on the bottom.See the G Force Crossmember Overview for more info.

This crossmember is installed with the G Force label facing the rear of the vehicle. However, another determining feature is the crossmember center tube which has a 1/2″ drain slot that is positioned on the bottom and on the passenger side next to the hump weldment.

This crossmember is installed so that the exhaust clearance humps are closed on the top and open on the bottom.

To use the provided 7/16″ hardware it is necessary to enlarge holes in your frame rails with a 1/2″ drill. If you choose to use the stock size 3/8″ hardware, it is strongly recommended to use new Grade #8 fasteners to compensate.

Discover more about the G Force Crossmember product line on these pages-

• What is a Crossmember
• Why Choose a G Force Crossmember
• Why Swap and What Is a Transmission Crossmember?
• A Next Gen Crossmember Maintains Strength
• Find the Right Crossmember for Your Project
• A Next Gen Crossmember - Why Weight Matters