TACO Marine Grand Slam 300 Universal Backing Plate Pair, For GS-300 & GS-390, 6.50 x 5 x 0.25 in, Brite Dip Anodized

Overview

The TACO Marine BP-0300BSY-1 is a Grand Slam 300 universal backing plate pair for GS-300 and GS-390 outrigger mounts installed through a T-top. Each plate measures 6.50 inches by 5 inches by 0.25 inches and uses a Brite Dip anodized finish, giving the outrigger base a clean finished look while adding support at the mounting point.

This backing plate is used under the T-top where the outrigger mount passes through, helping spread load around the base rather than leaving the fasteners working against a smaller area. Directional markers every 22.5 degrees line up with the locking detents of the compatible Grand Slam mounts, so the pole position can be checked at the base during setup and use.

Key features

• Made for TACO Marine Grand Slam GS-300 and GS-390 outrigger mount installations through a T-top.
• Pair of backing plates for port and starboard outrigger bases.
• Each plate measures 6.50 inches by 5 inches by 0.25 inches for fit planning around the mounting area.
• Brite Dip anodized finish gives the installation a clean appearance on visible T-top surfaces.
• Directional markings at 22.5 degree intervals align with the locking detents on compatible outrigger mounts.
• Matches the existing base hole pattern for compatible Grand Slam 300 and 390 installations, helping avoid unnecessary drilling when the setup is already laid out for these mounts.

Installation and fit

This plate is intended for through-T-top outrigger base installations where the GS-300 or GS-390 mount needs backing support and clear orientation reference. Before installation, confirm the available flat mounting area, hole pattern, fastener access, and clearance around wiring, pipework, canvas, or electronics mounted near the T-top frame.

The 0.25 inch plate thickness should be considered when checking fastener length and stack-up through the T-top. Final mounting should follow the outrigger mount installation requirements for the boat, with attention to sealing all penetrations and keeping the base properly aligned before tightening hardware.

Use on board

This backing plate is a good match for offshore and coastal fishing boats using Grand Slam outrigger mounts where the crew wants a cleaner T-top installation and an easier way to read outrigger angle at the base. The directional markings are useful when deploying, rotating, and stowing outriggers because the pole position can be checked without guessing from below.

What’s included

• One pair of Grand Slam 300 universal backing plates

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