Dynacorn 1967 Fastback Mustang Body
- Revolutionary Replacement
While over at
the Dynacorn
body, we put the
camera
underneath the
car for a look.
Behind the front
wheels are these
sturdy torque
boxes on both
sides. Borrowed
from the '68
Mustang design,
the boxes even
have gussets to
further
reinforce the
structure.
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Back at the
wheelhouse of
the original
Mustang, it's
easy to see the
void left by the
absent torque
box. The torque
boxes were used
on convertibles
but not on the
fastback. While
this arrangement
is fine for a
289 or 302, the
extra
reinforcement
provided by the
boxes would be a
welcome addition
to a car with a
390 or 428.
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Shock towers are
another important
structural area that
should be closely
examined. The towers
can bend and,
without the help of
a Monte Carlo bar,
travel inward over
the years. After 40
years of service,
the shock towers can
also develop cracks
that are difficult
to see. Big-block
engines and hard use
accelerate the
process. The
previous owner of
this car didn't help
matters any by
cutting open the
shock tower with a
blow torch just to
lubricate the
control-arm
cross-shaft. |
On the Dynacorn
body, the shock
towers are
patterned after
the '69
big-block
version. Notice
how another
separate layer
of steel jackets
the base of the
tower, resulting
in a much more
rigid assembly.
This
reinforcement
also found its
way onto Shelby
Mustangs built
during the
period.
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When we look
into the trunk
of the old body
shell, we find
the standard '67
hinges and a
torsion bar to
hold open the
trunk. The
hinges often
break, and after
time, the bar
becomes too weak
to support the
weight of the
trunk lid.
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In the back of the
Dynacorn body, the
trunk hinges are of
much heavier
construction and
patterned after the
'68 hinge. The
trunk-lid support
mechanism has been
changed to a coil
spring. The weak and
rattle-prone torque
arm is gone. |
The original
1010
automotive-grade
steel used by
Ford has been
supplanted by
universal-grade
1006 automotive
steel. The new
steel is an
improved formula
with fewer
impurities, and
it also has
better welding
characteristics.
As we have
heard,
thicker-than-stock
steel was used
in the
construction of
the new Dynacorn
body-let's have
a look. Here,
the core support
on our original
car shows a
thickness of
0.037 inch on
the micrometer.
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Looking at the
core support on
the new car, we
find a steel
thickness of
0.048 inch. The
0.011 increase
over stock is
certainly a
significant
amount. A more
rigid core
support will
certainly
benefit the
front box
structure.
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We chose the
fuel-fill hole
to take our next
thickness
measurement. The
thickness of the
tail-panel stamping
on the new car was
0.043 inch. |
We did our best
to scrape off
old paint and
came up with a
thickness
measurement of
0.034 inch. Once
again, the
difference of
0.009 inch is a
significant
amount of
improvement.
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The car's
doorskin
thickness was
another area of
interest to us.
The steel
thickness on the
Dynacorn door
was 0.033 inch
at the
door-handle
hole.
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The steel in the old
door measured 0.035
inch. However, the
presence of paint
and dirt on the old
door may have
spoiled the
measurement. We
suspect the Dynacorn
doorskin is at least
as thick as the
original door. In
any case, we can see
that the new
Dynacorn body is a
high-quality
offering for the
serious Mustang
restorer or custom
car builder, whether
it's used as a
replacement for a
rusted-out body or
as the basis for an
entirely new car
(which is what we
are about to build). |
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