Ford 351W Ready-To-Run Pro-Billet Distributor Steel Gear Ready-To-Run Distributors Include A Built-In Module. No Control Required. Includes An Steel Gear And A Rev Limiter MSD IgnitionThe billet aluminum housings of these distributors are 5 8 Inch smaller in diameter to accommodate induction setups and tight engine compartments. A maintenance free magnetic pickup is responsible for triggering the high voltage sparks while a sealed ball bearing guides an oversized shaft. Beneath the bolt down cap and MSD race rotor you'll find MSD's accurate mechanical advance assembly. Different advance springs and stop bushings are supplied so you