A-Premium Engine Rear Main Seal Cover Kit for GM OHV V8 4.8–7.0L — Complete Gasket & Seal Replacement

A-Premium Engine Rear Main Seal Cover Kit is a complete replacement cover assembly engineered to reseal the rear of OHV V8 engines (4.8L–7.0L) used across many Chevrolet, GMC, Cadillac, Hummer, Pontiac, Saab, Buick and Isuzu models.

This kit replaces the rear main seal cover and related seals and gaskets to stop engine rear-seal leaks and restore proper oil containment at the back of the crankshaft on overhead valve GM V8 engines. Built to match factory dimensions and indexed mounting points, the cover is supplied with a one-year unlimited-mileage guarantee and comes with part references for cross-checking compatibility. Below you’ll find concise answers to common fitment, installation, and performance questions, plus specific vehicle and dimension details to confirm this part fits your vehicle.

Will this rear main seal cover fit my vehicle?

Check the model years and engine family carefully: this A-Premium kit is designed for GM OHV V8 engines in 4.8L, 5.3L, 5.7L, 6.0L, 6.2L and 7.0L displacements and fits a wide list of Chevrolet and GMC trucks, SUVs, vans and high-performance cars. The product references and OEM cross numbers are provided so you can verify against your vehicle’s original part number before purchase.

• Compatible Chevrolet models include Avalanche, Camaro, Corvette, Silverado, Suburban, Tahoe, Impala and more (various years listed).
• GMC fitment covers Sierra, Canyon, Savana, Yukon and Envoy families across multiple model years.
• Also fits Cadillac Escalade/CTS, Hummer H2/H3, Pontiac models, Saab 9-7X, Buick Rainier/LaCrosse and Isuzu NPR variants.
• Cross-reference numbers: 635-518, 12633579, 12639250, 12615666, 12598301 and others for verification.

What are the key dimensions and part references I should confirm?

The kit lists clear physical dimensions and common reference numbers so you can confirm fitment without removing the old cover. Use these specs to match your engine’s rear cover dimensions and cross-reference the OEM numbers against your vehicle’s service manual or parts registry.

• Inside diameter: 2.7 inches — critical for seal seating around the crankshaft.
• Cover length: 10 inches and width: 6 inches — compare to the original cover outline.
• Reference part numbers included to cross-check: SK635518, 8-12633-579-0, 8-12639-250-0, and similar OEM codes.
• Includes gaskets and sealing components sized to the listed dimensions for a straightforward replacement.

How does the kit help during a rear main seal replacement?

The A-Premium kit supplies a direct-fit replacement cover and the necessary seals to restore a leak-free rear crankshaft interface, simplifying installation and reducing the need to source multiple parts. Quality-matched sealing surfaces and accurate mounting points make it suitable for professional shops and experienced DIYers.

• Complete cover assembly reduces parts hunting — seal and cover designed to mate precisely.
• Saves time by including compatible gaskets and seal components sized for listed engines.
• Manufactured to OEM-style dimensions to prevent misalignment and premature wear.
• Backed by a one-year unlimited-mileage guarantee for added confidence.

Who is this kit for? If you own or maintain GM vehicles with OHV V8 engines in the 4.8L through 7.0L range and you need a reliable replacement for a leaking or damaged rear main seal cover, this A-Premium kit is built to be a direct-fit option. It’s suitable for fleet technicians, independent mechanics, and confident DIYers who will verify cross-reference numbers and vehicle years before installation. Always confirm compatibility with the listed reference numbers and dimensions, and follow proper engine removal and installation procedures for rear main seal replacement.