1969-70 BOSS 429 FORD MUSTANG
While the Boss 429 Mustangs may not yet be the most desirable to
enthusiasts, (mainly due to their difficulty to just drive on the
street), they are certainly one of the rarest. Only 859 '1969'
models were built and 499 '1970' models. It should be noted that
all Boss 429 Mustangs were built in 1969 between January and
December. (January -July for the 69 and August - December for the
70).
The main reason the Boss 429 Mustangs were built was so Ford could
race their new "Shotgun" engine in NASCAR. The rules were that to
race an engine it had to be fitted to at least 500 production units
that could be sold to the public. This was called homologating.
This enormous engine, a true 'Hemi' that put out 400 HP off the
showroom floor, could easily have been fitted into any number of
larger Fords, that were racing at the time, with very little
trouble but it was the image they wanted with the Mustang to
attract younger people. This being the case the Boss 429 had to
basically be hand built as the shock towers had to be moved out and
suspension arms lowered, just to initially sqeeze it in. (This is
before any work was done on the steering, brakes, exhaust and body
etc).
This job was given to a company called Kar Kraft who were
contracted to the Special Vehicle Division of Ford and located in
Dearborn, Michigan. Due to the number of cars Ford needed built and
the urgency, the company moved their operation to a former assembly
building and the lot of a mobile home manufacturer in Brighton,
Michigan.
A stripped down Mach 1 Mustang being
tranformed at Kar Kraft into a Boss 429.
By December 1968 the race engine had been sufficiently detuned and
the prototypes and crash test cars had been thoroughly checked out.
Job #1 rolled off the line on January 15, 1969. Apart from slight
engine modifications and the small style changes between the two
models, the main differences between the 69 and the 70 was the 69
only came with a black interior and the 70 had a choice and on the
69 model the large bonnett scoop was painted the same colour as the
car where as on the 70 model they were all painted black. (This was
due to problems of different coloured paints peeling and colour
matching onto the fibreglass scoop).
  Modifying the suspension and exhaust at Kar
Kraft on Job #1 was a team effort. |
The Boss 429s race debut was the 'Atlanta 500' on March 30 1969.
They finished first and second and went on to dominate the 1969
season with 26 first place wins. (The Boss 429 was raced in the
slippery nosed Torino Talladega and the Cyclone Spoiler II, but not
the Mustang). Things got a little out of hand by the end of 1970
with rules and regulations and Ford pulled its support in drag
racing and NASCAR. Today though, along with the Dodge Hemi, it is
still one of the dominate engines in race/drag/boat competition.
Note. Two street versions of the Boss 429 engine were
built. The first few hundred were designed for heavy duty use and
were designated "820-S". They use a super tough crank, rod and
piston combo. Later 'street' versions are called "820-T" and use a
different crank, rod and piston. All "S" engines and early "T"
engines came with a hydraulic cam. Late '69 "T" engines and all '70
"T" engines use a mechanical cam, the same one as used in the
429-SCJ (Super Cobra Jet) engines. There was also the race only
NASCAR 429 motors with different heads, rocker arms and
reciprocating assembly.
BOSS 429 ENGINE PAGE
The Mustang Shop
