What terror lies beneath your convertible top? It may sound like a tag line from a low-budget Hollywood horror movie, but be forewarned. When you prepare to install a new canvas on your classic Pontiac drop top, you may find that the header bow has been hiding a dirty, little secret—rust.
The header bow is the far front sub-assembly of the convertible top frame. Most likely, yours is either original to your classic Pontiac or sourced from a donor car, as GM-licensed reproductions were not available until 2000 (’67-’69 Firebird) and 2010 (’66-’67 and ’68-’72 A-body), forcing owners to retain these original units, despite their condition.
For this story, a ’68 Firebird convertible, which previously had its top removed, will serve as the example, though you may use the information we provide for ’66-’72 GTO, LeMans, and Tempest convertibles, too. (Currently, there are no reproduction header bows for the ’64-’65 A-bodies or the Pontiac full-size convertibles.)
The Firebird is a West Coast car with a quality restoration performed back in the ’90s. Except for one small rust spot on the driver’s floor pan (which is typical to GM convertibles of the era), all of its body panels are original with no rust-through. We were surprised to discover the header bow had significant rust damage, primarily along its perimeter lip.
This GM diagram illustrates...
This GM diagram illustrates the main and sub-assemblies of the convertible top
mechanism. The header bow is referred to as the front roof rail here.
The header bow attaches to...
The header bow attaches to the
convertible-top frame assembly
with four fasteners: a No. 3 Phillips head
screw and a 1
/2-inch nut (mounted on a
permanent stud) on both the driver and
passenger sides of the car. Ernie uses a
hammer and an impact driver to break
the first No. 3 Philip screw loose prior to
removing it.
He removes the 1
/2-in nut...
He removes the 1
/2-in nut with a
socket wrench. (Note: The stud
remains in the convertible-top frame.) He
then repeats the steps on the opposite
side.
“Prior to the introduction of Goodmark’s reproduction header bow, body shops would typically invest 15 to 20 hours of labor into repairing an original piece for a GTO or Firebird,” says Steve Dietz of Florida Pontiac (www.floridapontiac.com). “That could translate into a $500 to $750 cost or more to the customer.”
In comparison, Goodmark’s OE-replacement header bow is reverse engineered from a factory unit to assure an OE-type fit. It’s stamped from 18-gauge steel like the originals, and comes painted in semigloss black. It retails for $362.95.
We enlisted the expertise of Ernie’s Auto Trim in Pinellas Park, Florida, to show how easy it is to install one.
With the four fasteners removed,
Ernie...
With the four fasteners removed,
Ernie easily separates the header
bow from the convertible-top frame, as
shown.
He slides the latch mechanisms
down...
He slides the latch mechanisms
down and out of the header bow.
Check out that poor OE welt (pinchweld
finishing lace), which is deteriorated from
dry rot.
He will strip the old paint...
He will strip the old paint off the
latches, and apply fresh coats.
Since our spring-actuated lock hooks are
in good shape, we'll reuse them.