The bare frame for the project came from a local British auto wrecker. It was
sandblasted prior to working on it. All components to be
mounted on the frame were acquired ahead of time to study their required dimensionality -
the Corvette rear suspension, a 4 spd. muncie
transmission, and an empty, cleaned and painted Chevy small block.
The new frame components were fabricated and temporarily
bolted together, and aligned. Donsco Offroad Vehicles, of Belmont, CA was commissioned
to do the welding - my life is riding on those welds.
Stock Spitfire half-shafts cross over the frame. Vette independent rear suspension half-shafts
cross underneath the frame. The 1964 Vette rear suspension is a
complete assembly comprised of third member, transverse spring, half-shafts, brakes, and
various other components. The rear portion of the stock Spitfire frame had to be modified to
accept the Vette rear suspension which requires an overhead frame member on which to mount the
differential. The rear portion of the stock frame was removed and the Vette rear suspension
mounting modifications were added. The stock Spitfire frame is
constructed in the shape of an hour-glass with a solid connector between the two frame
rails. The connector is used for the rear transmission mount. The hour-glass
design of the stock frame would be subject to high forces tending to warp the frame
laterally. Therefore, two lengths of 2 inch x 2 inch x 1/8th inch square steel tubing were
added that ran from the rear frame mods to the front of the frame modifying the
'hour-glass' frame to an 'H' frame with cross-member for stability
under the extreme torque of a V8 engine. The resulting frame was very rigid and has worked
flawlessly. The frame was then primed and painted - powder coating was not available. The engine,
running gear, and suspension were mounted prior to placing the body on the frame to ensure
the best alignment of components. The driveshaft was shortened appropriately.
The first diagram depicts a stock Spitfire frame in the hour-glass design. The second diagram
shows a view of the overall modified frame in the 'H' layout. The third diagram shows the detail
of the modifications necessary to mount the Vette independent rear suspension.