1970–74 Mopar E-body (Challenger, Barracuda/'Cuda) chassis

5 aftermarket chassis and subframes from 3 builders, compared with keeping and upgrading the original frame.

Roadster Shop, Schwartz Performance, Speedtech Performance

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Aftermarket chassis

Prices checked Oct 2, 2026

Builder & product	Type	Front	Rear	Price
Original chassis Keep it and upgrade itUnibody with front frame rails and a bolt-in K-member (B-body-derived front structure)	Factory	SLA with torsion bars, strut rods; recirculating-ball box	Solid axle (8.75 / Dana 60) on leaf springs	Kits from $7,293.90Cheapest kit in each area
Speedtech Performance 1970-1974 Mopar E-Body Torque Arm Rear Suspension	Rear suspension	n/a	Torque arm with trailing arms	$5,299.95 Listed price Source
Speedtech Performance 1970-1974 Mopar E-Body Extreme Subframe	Front subframe	Forged spindles with C7 hubs, Sweet rack, sway bar, optional coilovers	Not included	$9,699.95 Listed price Source
Speedtech Performance 70-74 E-Body Independent Rear Suspension	Rear suspension	n/a	IRS, C7 hubs, alum 9in, CV axles, cradle	$19,999.95 Listed price Source
Roadster Shop 1970-74 Challenger/Cuda FAST TRACK	Full frame	RS Fast Track IFS, 58.75in track, C7-based forged knuckles, sealed hubs, RS SV by Fox coilovers, 1.25in splined sway bar	Large-dia parallel 4-bar, Strange Ford 9in, S/S 31-spline axles; Fast Track IRS optional	$22,495 Base $22,495 (category listing 'From $22,495'); product page shows 'From $22,695' Source
Schwartz Performance 1970-1974 E-Body, Challenger, Cuda G-Machine Chassis	Full frame	Double A-arm coilover, power rack, sway bar	Full-floating 9", 31-spline; IRS optional	Quote only Source

Tick up to 4 to compare side by side.

Reading these prices

Starting prices aren't always comparable. Some include suspension, steering and brakes; some are a bare frame or front clip and the rest is extra. Check the Front and Rear columns and each product's notes before comparing totals. "Price on request" means the builder quotes each build. Confirm with the builder before you order, and send corrections through our contact page.

Upgrade the original chassis

How it's built: Unibody with front frame rails and a bolt-in K-member (B-body-derived front structure)
Front suspension: SLA with torsion bars, strut rods; recirculating-ball box
Rear suspension: Solid axle (8.75 / Dana 60) on leaf springs
Weak spots: A short, wide unibody that is flexy, especially as a convertible, and the rails are not connected. Soft torsion bars, rubber bushings and a slow box limit handling.

Stiffening the body or frame? We list 6 kits for this car, such as frame rails, subframe connectors and braces, on its Chassis stiffening page.

Suspension and steering kits for the original chassis

Area	Kit	What it does	Price
Front suspension	Hotchkis TVS Suspension System 80111 (70-74 Challenger)	Upper arms, adjustable struts and tie rods, bars, leafs, subframe connectors, shocks	$4,054.95 Hotchkis list Source
Front suspension	QA1 Front Coilover System 52346-S400 (B/E body)	Bolt-in tubular K-member, rack and coilovers	$5,524.95 QA1 list Source
Front suspension	Reilly Motorsports (AlterKtion) AlterKtion Pro System, Street/Handling, 70-74 E-Body RMS603	7.25in travel, power rack, Wilwood Pro spindles; bolts to the factory rails	$5,995 Reilly list Source
Rear suspension	QA1 Rear Four Link System R255-175 (double adj, 8-3/4)	Triangulated 4-link coilover conversion; welding required	$2,688.95 QA1 list Source
Steering	Firm Feel E-body Power Steering Box Rebuild	Fast-ratio rebuilt box with firmer reaction springs	$550 $550-$595 by stage plus $250 core Source