These bushings take the “movement” out of a new or old front end while providing the superior suspension qualities that only urethane can provide. Since urethane is impervious to the elements and wear like “iron”- you’ll enjoy many years of performance. In/Out bushings are long one piece units designed to replace BOTH inner and outer with one bushing at the same time giving greater surface to the trailing arm (incl custom aluminum and steel beams) while the others replace the outer only.
Learn more from the following Mid America Motorworks Knowledge Library articles:
Vintage VW's: Why Use Urethane / Polyurethane for Your Suspension?
EMPI