<%@ Page language="C#" %> <%@ Register assembly="gdsWebControls" namespace="Gds.WebControls" tagprefix="GdsWebControls" %> C4 Corvette Removable Tops Informational Guide

C4 Corvette Removable Top Informational Guide

 During the course of C4 Corvette production there were options for three different tops or roofs.  There was the standard removable top, in 1986 the convertible was made available and then in 1989 the hardtop convertible option was available.

This informational guide's main focus is the removable tops (Commonly referred to as Targa tops) and their various changes throughout C4 production.   Note* The term Targa means a semi-convertible car body style that employs a removable roof section, and also a full roll bar behind the seats.  The term was first used on the 1966 Porsche 911 Targa.   At the time of this writing Targa remains a registered trademark of Porsche.  

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Removable Top Types

Removable tops were available in two styles, a solid painted fiberglass, and an acrylic transparent top.  The fiberglass tops were painted to match the exterior color car.  However, no matter what the interior color of the car was, the inside headliner was always black using a material matching that of the sunvisors.   

The transparent tops were the most popular option for C4 Corvettes.  However, there was an option to order cars with both a transparent and painted top from the factory starting in 1986.  This option is designated as RPO code C2L.  

Transparent Top Colors

1984-1985: Smoked Grey (CC3) (Though most people agree these have a blue tint) 1986-1996: Blue (24S) or Bronze (64S)  

Various sources mention that the bronze top (RPO code 64S) for the 1994-1996 model years was different than the bronze 64S of 1986-1993 model years.  Customers ordering their Corvette from the factory did not have a choice as to which color top was provided as this was determined by exterior and interior color combinations during production.  Check your RPO codes to determine your cars original top color.  

Mounting Variations

If you are looking for a replacement top for your C4 Corvette it is important to remember that the front attachment hardware design changed three times between the years of C4 production.   The difference in design can be identified by the distance between the front mounting bolt location, or the design of the hardware on the underside of the top.

1st Design (1984 Early 1986) 28" on center distance between front mounting bolts.

2nd Design (Late 1986 1988) 31.5" on center distance between front mounting bolts.

 

3rd Design (1989 1996) 32.5" on center distance between front mounting bolts.

 

Note* Often you can tell an aftermarket replacement top from an original top by the use a rubber molding strip around the outside edge of the top.  Original tops used a metal molding trim that was painted black. 

Windshield Brackets - Mixing and Matching Various Years

A frequent question we hear is where the customer has an earlier, say 1984-1988 corvette, and has recently found a nice used top from a 1989-1996 car and they would like to know how to make the top applicable to their car.   The solution to this is to change the brackets at the top of the windshield to match the top that will be applied.

You can apply any year C4 targa top, to any year C4 Corvette as long as the brackets on the car are from the same year range as the top.

The bolts which hold the brackets onto the car are in the same position for all years, so changing brackets is a simple bolt on change. (We usually always have these brackets in stock) Changing the brackets will also require changing the top trim covers and either replacing or modifying the windshield header panel. (See below)

For non original owners of all years, it is important to verify the distance between the front mounting bolts on the hardware of your car as it may have been modified in the past.   

When GM introduced the 1989 models, they began offering the updated windshield hardware when the 1984-1988 cars needed a replacement top. This allowed for the older cars to be updated with newer tops and for GM to produce only a single top design from 1989 onwards.

Many times it is easier to locate a nice used 89-96 top than it is to find one for earlier years. Especially 1984-early 1986 tops. If looking for a used replacement top for these earlier cars, consider a top and brackets from a later car to simplify your search.

Windshield Header Panels

The interior windshield header trim also varied as the holes in this trim piece, which allow access to the front mounting bolts of the top, are in different locations for the various year tops.  Therefore header trim needs to match the year ranges of avaiable tops. (84-86e, 86L-88, 89-96)

Several different GM part numbers exist for these header panels even within the specified year ranges.  Therefore, in case of replacement it is important to verify the distance between the bolt access holes of the header trim so that they will match the year top of your vehicle.  If they do not, you will need to drill new holes in the replacment header trim.  On the 89-96 header trim pieces there is a note on the inside of the plastic trim (shown in the photo below) which indicates that holes need to be drilled should the 89-96 trim pieces be applied to an earlier corvette.

Please feel free to give us a call or contact us at info@mirrockcorvette.com with any questions.

 

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