Unique Physical Attributes of Chassis SPL 224/B – AHS 3804

The following details set AHS 3804 apart from the other “production” Austin Healey 100S chassis and provide evidence of its identity as a Special Test Car, the 3-time Mille Miglia entrant, and Phil Stiles’ 1956 Sebring car. Many of these details were pointed out by Roger Menadue and Geoffrey Healey during their inspection, and were researched extensively by the car’s current caretaker.



  • Aluminum alloy outer body panels
  • Cockpit trim pieces stamped “Racer 24” providing a direct link to NOJ 391
  • Riveted lower front wings, unique to the SPL cars only
  • Riveted aluminum alloy sub-structure
  • Enlarged wheel arches to clear 16” Dunlop wheels fitted for the ’54 season
  • Corrugated boot floor with mounting holes for Marston-Excelsior fuel tank
  • LH battery box area cut to accommodate standard 100 LH exhaust; the correct specification prior to its works 100S conversion, with RH exhaust
  • Additional vents cut into lower front apron for oil cooler
  • Steeper windscreen rake than production 100S, documented in period photos
  • Scuttle drilled for individual aeroscreen & tonneau retainer as pictured in the Mille
  • Layers of paint revealed down to original light metallic green
  • Rear inner wheel arch depressions removed to clear the 16” wheels
  • Evidence of exterior door handles fitted for the 1954 Mille
  • Cooling duct in RH wheel arch for brake master cylinder



  • Chassis frame with raised, gas-welded seam – consistent with the 1954 chassis change. The original pre-production cars had a flush seam.
  • Hand-made, gas-welded suspension pickup points, later adapted to production 100S chassis
  • Various gearbox mounting points evident
  • Heavier steadyrest for gearbox mount
  • Chassis cut/welded to provide clearance for the gearbox-driven power brake pump
  • Gas welded brackets for early style Marston-Excelsior oil cooler, later changed to 100S barrel-type oil cooler
  • Unique rear quick-lift jack points, different from production 100S
  • Roll bar and pickup points as added by Bobby Berger
  • Sump guard mounting points



  • Lucas competition Master Switch, fitted for Mille Miglia and endurance events
  • Lucas competition wiring loom
  • Dual Lucas ignition coils
  • Spark plug holder
  • Spare wheel hoop made for 16-inch wheel
  • Holes in front apron for auxiliary light stiffeners
  • Black upholstery with red piping, consistent with period color photos. The “other” OON 440 had blue upholstery in period

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