Street Connection is Hammer Fab's suspension and chassis system for Mopar A-Body cars, developed in Bertram, Texas and validated on our own 1967 Barracuda. This guide explains how the system works as a whole — what comes off the car, what goes on, what has to be welded, and which decisions you should make before you order.
Factory A-Body suspension, in context
From the factory, an A-Body runs a torsion-bar front suspension with a steering gearbox and a stamped K-member carrying the lower control arms. Ride height is set by cranking on the torsion bars, the steering box and its linkage sit ahead of the crossmember, and the unibody carries the suspension loads through the floor structure.
Street Connection replaces that entire front architecture — K-member, torsion bars, and steering gearbox — rather than adding parts on top of it, so ride height, steering, and spring rate are no longer tied together.
Coilover conversion
RideTech adjustable coilovers replace the factory torsion bars. Ride height becomes an adjustment at the shock body instead of a torsion-bar preload, damping and spring rate are selectable, and the suspension is controlled by components designed to work together.
- Eliminates the factory torsion bars entirely
- Adjustable ride height front and rear
- Multiple spring-rate options available
- Mustang-style upper and lower control arms with rubber bushings — comfortable street manners without the harshness of polyurethane, Delrin, or solid rod ends
- Wilwood Pro dropped spindles
Rack-and-pinion steering
A Detroit Speed rack-and-pinion replaces the factory steering gearbox and linkage. It uses conventional tie-rod ends and is packaged so the steering geometry works with the rest of the system rather than requiring bulky bump-steer correction hardware bolted on afterwards.
Hammer Fab billet aluminum dropped steering arms set the outer tie-rod height to match the rack and dropped spindles.
Suspension geometry and alignment targets
The A-Body system is built with -6 degrees of caster designed into the geometry, with camber landing at approximately -0.5 degrees at ride height with the full weight of the car on the suspension.
Camber and caster adjustment is handled with alignment shims at the upper control arm — the same simple, serviceable method a shop is already set up for. The kit ships with baseline shims that get the car close enough to load and move at low speed, but a professional alignment is required before driving at road speed.
The Street Connection K-member
The K-member is the foundation of the system. It carries the control arms, the coilovers, the rack, and the engine mounts, and it is fixture-built so fitment repeats car to car.
- Can be installed as a bolt-in or weld-in unit
- Fixture-built for repeatable fitment
- Designed around multiple engine configurations
- Supplied in bare steel, which also lets experienced builders fabricate their own mounts for engine combinations outside the supported list
Chassis reinforcement
A unibody A-Body benefits from being tied together before you ask more of the suspension. Street Connection uses weld-in mid-frame stiffeners — 10-gauge laser-cut steel, contoured from 3D scans of the factory floor — to connect the front and rear structures.
- L-channel design: heavy 10-gauge steel, no enclosed moisture traps, and all surfaces remain accessible for coating
- Welds to the factory floor pan — cutting the floor is not required
- Welding along a single primary edge helps limit floor-pan distortion
- Especially recommended above roughly 350 horsepower
- Rear frame stiffening plates and 10-gauge weld-in crossmembers add further rigidity
Engine packaging
The K-member was developed around real installations, not theoretical dimensions. Rear-sump oil-pan requirements vary by engine.
Big-block Mopar (B/RB)
361, 383, 400, 413, 426, and 440. Our 1967 Barracuda test car runs a 440 big block today. That combination fits under the stock hood, without cutting the factory floor pan, with roughly 4" of oil-pan ground clearance when configured appropriately. A modified Dodge truck rear-sump oil pan is required.
LA small-block Mopar
273, 318, and 340. Fitted and tested with a 340 in a Formula S. Requires a Dodge truck rear-sump oil pan and the appropriate pickup; the pan can be modified for extra ground clearance but modification is not mandatory.
Gen III Hemi
Supported with the appropriate rear-sump oil-pan configuration. Hellcat applications require editing sheet metal. Hammer Fab also offers Street Connection-specific stainless Gen III Hemi headers designed around this K-member, steering, and suspension package.
Other combinations
The bare-steel K-member allows experienced builders to fabricate custom engine mounts. If your engine is not listed as a supported configuration, contact us before ordering.
Rear suspension
The rear is a triangulated four-link built for articulation, strength, and predictable street behavior.
- Triangulated four-link with RideTech R-Joints and adjustable geometry
- Heavy-duty Ford 9" housing in raw steel with Torino-style ends and GearFX 31-spline axles
- Fixture-built, TIG-welded rear-end brackets
- RideTech adjustable rear coilovers with multiple spring-rate options
- 10-gauge weld-in crossmembers tying the floor pan to the side frame rails
- 10-gauge rear frame stiffening plates (weld, fit, and finish-grind during install)
- Optional: rear splined sway bar, Baer SS4 rear brakes, upgraded third-member and axle configurations (Moser third member, 31- or 35-spline, multiple gear ratios)
Wheels, brakes, and alignment
Wheels and tires are not included. 5x4.75" is the Hammer Fab standard bolt pattern and the kit is typically built that way; 5x4.5" is available by request and can be confirmed with us after the order is placed.
A minimum 18" wheel is required with the Baer brake packages on all Street Connection kits. Plan your wheel selection around that before ordering brakes.
Available brake upgrades
- Baer T4 front disc brakes — satin-black calipers, 5x4.5" and 5x4.75" available
- Baer SS4 rear disc brakes
- Baer ReMaster master cylinder package — billet master cylinder, proportioning valve, brake line kit, two residual-pressure valves
A professional alignment is required before the car is driven at normal road speeds.
What installs, what welds
This is a fabrication-level system. Much of it bolts together, but welding is part of the job.
- Bolt-in: the K-member can be installed as a bolt-in unit, along with the control arms, coilovers, rack, spindles, and steering arms
- Welding required: mid-frame stiffeners, rear crossmembers, rear frame stiffening plates, and the rear four-link mounting structure
- No floor cutting is required for the mid-frame stiffeners
- Fitting, finish grinding, coating, and a professional alignment should all be planned into the job
If you are not doing your own welding, budget for a shop that can. We do not publish install hour estimates — the work varies too much car to car.
Development and testing
Street Connection was developed on SLOBAK, our 1967 Plymouth Barracuda — a car that gets driven on the street and run at autocross, currently powered by a 440 big block. Components are fixture-built so what we validated on our own car is what ships to yours.
Before you order
- Confirm your engine combination and rear-sump oil-pan plan
- Choose your bolt pattern — 5x4.75" standard, 5x4.5" by request
- Confirm wheels are 18" or larger if you are selecting Baer brakes
- Select gearing based on engine, transmission, tire diameter, and intended use
- Line up welding capability and a professional alignment
- Freight terms and configuration options are covered on the product page — freight is quoted separately after the order