The 302 to 347 Windsor Conversion

The Ford 302 Windsor is one of the most widely used small block platforms in performance building. Its compact dimensions, broad parts availability, and proven architecture make it a natural starting point for a stroker build. By fitting a longer-stroke crankshaft along with matched connecting rods and pistons, the 302 block becomes a 347 cubic inch engine - a 15 percent increase in displacement without any change to the external dimensions of the motor.

Build Overview

In this video, Sydney Speed Supplies walks through a Ford 302 to 347 Windsor stroker motor assembled using Speedmaster components. The stroker kit provides the core of the conversion: a new crankshaft with increased stroke, connecting rods sized to match, and pistons designed to deliver the correct compression ratio and deck height for the 347 combination.

The 347 Windsor is a well-established recipe in the Ford small block world because the numbers work. The stroke increase falls within what the 302 block can accommodate without clearancing issues in most cases, and the resulting displacement puts the engine in a torque range that works for both street and strip applications.

Why the 347 Combination Works

Torque is a function of displacement and cylinder pressure. By increasing the stroke, each combustion event pushes the piston through a longer power stroke, extracting more work from the same air-fuel charge. The 347 Windsor delivers noticeably more low-end and mid-range torque than the standard 302 - the kind of improvement that is felt immediately behind the wheel.

Paired with the right heads, cam, and intake, a 347 Windsor stroker is capable of producing well over 400 horsepower on pump fuel. This build from Sydney Speed Supplies demonstrates the assembly process and shows what the finished combination looks like, ready for installation.