Keep your classic Ford or Mercury running clean and strong with this premium 2-piece polyacrylate rear main crankshaft seal from LowPricedAutoParts – the trusted retailer of automotive parts and accessories dedicated to outstanding customer service. This high-quality offset seal (shaft diameter 3.750", seal OD 4.321", width 0.220") is precision-engineered for the popular Ford 5.8L (351 CID) Windsor V8 engines in 1969–1979 models including Ford Mustang, Torino, Galaxie 500, LTD, Fairlane, Ranchero, Custom 500, Country Squire; Mercury Cougar, Montego, Colony Park and related full-size classics. These timeless Ford Windsor V8s deliver smooth power, impressive torque and legendary reliability – favorites for muscle cars, family wagons, cruisers and light-duty trucks in the muscle car era. Owners love their straightforward maintenance, strong performance and abundant parts availability for restorations or daily driving. Over time, however, the original rear main seal can harden, shrink or wear, allowing oil to seep past the crankshaft and create drips, low pressure warnings or messy bellhousing areas. This premium polyacrylate 2-piece replacement effectively stops those leaks, restoring factory-like dryness and confidence. Polyacrylate material provides superior heat resistance, oil compatibility and flexibility, while the offset double lip design enhances protection against oil loss and contaminants compared to basic seals. It's a direct-fit upgrade that maintains proper crankshaft support during high-mileage service, clutch replacements, transmission swaps, oil pan gasket jobs or complete engine overhauls on these durable V8s. Installation is straightforward for experienced mechanics: Thoroughly clean all sealing surfaces and the crankshaft flange, inspect for grooves or damage (consider polishing or a repair sleeve if needed), apply appropriate assembly lube or sealant per Ford guidelines, position the two-piece seal halves correctly with offset alignment without distortion, reassemble the rear cover with even torque sequencing, and monitor closely during initial startup and break-in. Professional help is advised if measurements or alignment raise any concerns. At LowPricedAutoParts, customer service is our top priority. Message us your VIN, engine details or any fitment questions – our knowledgeable team is ready to confirm compatibility quickly and provide the personalized support you deserve. Shop with confidence knowing you're getting a premium rear main crankshaft seal backed by exceptional service. We're here to help get your Ford Mustang, Torino, Galaxie 500, Mercury Cougar or similar 5.8L Windsor classic sealed tight, running clean and ready for the road again – contact us today!