Fiberglass 911 Cab Hardtop Installation

(this is a work in-progress)

Expectations

Before we begin, I would like to establish some expectations. Due to the nature of these cars, composites, and the inherent complexities of the cab top in general, it is unrealistic to expect it to bolt right on out of the crat and away-we-go. Every single car is slightly different straight from the factory, and certain parts are built so the fit can be adjusted on the car. Examples are doors, hoods and engine lids. The OEM convertible top is the same way; the original top is adjustable in several different ways:

The three mounting brackets across the back window can be adjusted for and aft by loosening the bolts that attach the brackets to the body.
The rear of the top can be adjusted up or down by loosening the bolts that attach the top to the brackets
The B-pillar hinge can move fore and aft, and side to side. In addition, the factory supplied plastic spacers to raise the top if necessary.
There is an adjusting rod that attaches below the B-pillar mount
The position of the top latches can be adjusted

Each time the factory top is removed, the entire adjustment process must be repeated.

When installing the fiberglass hardtop, the initial adjustments are done by making small physical alterations to the top, ie sanding or filing small amounts of material to get the desired fit. Once the initial installation is done, you can remove and replace the top without having to go through the entire routine again.

Installing this hardtop requires a mild level of mechanical and bodywork expertise. It requires a skillset similar to that required to install fiberglass quarterpanels - you will need to be able to trim material and properly guage the fit of the part. It is strongly recommended that the installation be carried out by a shop that's familar with working with composites.

Other parts you will need to source

There are a few things that you will need to find in order to complete your hardtop install

Latches - targa or cabriolet latches to match your windshield header. Pre-1986 uses 'hook' latches, post '86 uses 'roller' latches
Windows - rear and quarter windows (and seals) from a 1995 or earlier 911 coupe
Seals - targa or cab door window seals
Small "L" brackets for rear of top

Tools

If you are doing the work yourself, you will need some basic automotive and bodywork tools.

file/rasp/SureForm - for shaping fiberglass
drill - for drilling mounting holes
sanding block or D/A sander
large clamps with wide, non-marring pads

Supplies

painters blue masking tape
3M Super Weatherstrip Adhesive
varying grades of sandpaper from #60 to #400

Installation High-level Overview

uncrate the top and make sure it hasnt' been damaged in shipping.
remove existing top
apply blue tape to windshield header and body mount area so you don't damage your paint.
set top in position, back-end first, to guage initial fit
work back-to-front, making any adjustments to achieve desired fit. You may have to remove small amounts of material to get the fit even.
once you get the rough fit, install the body seal, then re-check the fit, starting at the back and moving forward.
use clamps to hold top tight against the body.
when you're happy with the fit, install rear brackets (under rear window)
drill and bolt down B-pillars
install front latches or bolts.
perform finish bodywork and paint
install seals and windows

Part numbers:

Seals
Description	Part Number	Comments
Targa Top Side Seal, 911 (1974-89)	911 565 259 40 (left) 911 565 260 40 (right)
Cabriolet Vertical Door Window to Top Seal, rear, 911 (1983-85)	911 561 221 01 (left) 911 561 222 01 (right)	You can also use the outer sections of the Targa bar seal 911 565 091 45
Latches and handles - up through 1985
Description	Part Number	Comments
Targa Top Catch (sold per each, 2 required), 911 (1974-85)	911 565 031 41	For pre-1986 cars
Targa Top Handle, 'Updated Version' 911 (1967-85)	911 565 075 41	2 required
Latches and handles - 1986 and later
Description	Part Number	Comments
Targa Top Catch, 911 (1986-89)	964 565 031 00 (left) 964 565 032 00 (right)	For 1986 and later cars
Targa - Cabriolet Top Handle, 911 (1986-89)	911 565 075 62	For 1986 and later cars, 2 required