1966–70 Mopar B-body (Charger, Road Runner, GTX, Coronet) chassis stiffening
6 kits to stiffen the body shell, from frame rails and connectors to braces and roll bars.
- How it's built
- Unibody with welded-in front frame rails and a bolt-in K-member
- Weak spots
- A long, heavy unibody with unconnected rails, so it flexes under big-block torque. Soft torsion bars, rubber bushings and a slow box give heavy roll and poor feel.
Stiffening kits
| Area | Kit | What it is | Price |
|---|---|---|---|
| Subframe connectors | Competition Engineering Subframe Connectors 1966-72 Chrysler B-Body (C3117) | Bolt-on, no welding. | $276.99 JEGS price, pair Source |
| Subframe connectors | X-Parts / AMD (USCT-made) Weld-in Frame Connectors - 66-70 Dodge Plymouth B-Body (X896-1466-P) | Welds to floor pan from underneath, no floor cutting. | $319.99 AMD price; $14.99 oversize fee Source |
| Subframe connectors | Hotchkis 4010 Subframe Connector Kit, MOPAR B-Body | Fitment table lists 1968-70 B-bodies. | $499.99 Hotchkis list price Source |
| Subframe connectors | US Car Tool Level 1 Chassis Stiffening Kit 66-70 B-Bodies (USC1M1013) | Weld-in frame connectors plus four torque boxes. | $762.99 Mancini Racing price Source |
| Frame stiffening | Hotchkis Subframe Connector Kit 4010 | Connects the front and rear rails on 66-70 B-bodies | $499.99 Hotchkis list Source |
| Shock & strut tower braces | Not stated (Mancini Racing listing) Inner Fender Brace Kit 66-70 B-Body (USC1M1201) | Boxes shock tower top and ties it to fender; recommended for coilover conversions. | $289.99 Mancini Racing price Source |
Prices are from the linked seller pages and change often. Confirm fitment for your exact year and body style before ordering; many weld-in parts need professional installation. Some links earn us a commission.
Get the Deal Finds first
The best classic-car finds we spot on eBay, Marketplace and Craigslist, plus new build guides. One email a week.