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Looking for aftermarket parts to modify or upgrade your 1978 GMC C15 with gasket kits? At Tunersports.com we carry a huge selection of the top name brand performance gasket kit parts and accessories.
 SHIPS FROM MANUFACTURER C5682Cometic Chevrolet Mark-IV Big Block V8 Rear Main Seal - 2 Piece 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $60.14 |
 SHIPS FROM MANUFACTURER C15550Cometic Chevrolet Gen-IV Big Block V8 One Piece Molded Rubber Oil Pan Gasket 1965-1990 1975-1978 GMC C15 Base / High Sierra / Sierra Classic 1977-1978 GMC C15 Heavy Half $77.02 |
 SHIPS FROM MANUFACTURER C15607Fully cured nitrile butadiene rubber binder for maximum fluid resistance... Cometic Chevy Mark-IV BB V8 .094in Fiber Oil Pan Gasket Kit 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $59.74 |
 SHIPS FROM MANUFACTURER C5344Fully cured nitrile butadiene rubber binder for maximum fluid resistance... Cometic Chevrolet Mark-IV Big Block V8 .094in Fiber Oil Pan Gasket Kit - Trimmed Side Rails 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $59.74 |
 SHIPS FROM MANUFACTURER C5344-060A chemically blown, compounded nitrile synthetic rubber bonded to an aluminum core... Cometic Chevrolet Mark-IV Big Block V8 .060in AFM Oil Pan Gasket Kit - Trimmed Side Rails 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $63.72 |
 SHIPS FROM MANUFACTURER C5344-075A chemically blown, compounded nitrile synthetic rubber bonded to an aluminum core... Cometic Chevrolet Mark-IV Big Block V8 .075in AFM Oil Pan Gasket Kit - Trimmed Side Rails 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $54.59 |
 SHIPS FROM MANUFACTURER PRO1003BCometic Street Pro Kits are geared toward the street rider who is looking to purchase a kit with all necessary gaskets and seals needed for your rebuild.... Cometic Street Pro GM 1967-88 350ci 1970-76 400ci Small Block Bottom End Gasket Kit 1975-1978 GMC C15 Base / High Sierra 1977-1978 GMC C15 Heavy Half $104.43 |
 SHIPS FROM MANUFACTURER PRO1003TCometic Street Pro Kits are geared toward the street rider who is looking to purchase a kit with all necessary gaskets and seals needed for your rebuild.... Cometic Street Pro GM 1967-88 350ci 1970-76 400ci 4.165 Small Block Top End Gasket Kit 1975-1978 GMC C15 Base $262.38 |
 IN STOCK - LOW PRO1005BCometic Street Pro Kits are geared toward the street rider who is looking to purchase a kit with all necessary gaskets and seals needed for your rebuild.... Cometic Street Pro GM 1970-85 454ci Big Block Bottom End Gasket Kit 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $75.58 CLEARANCE VIEW PRICE IN CART |
 SHIPS FROM MANUFACTURER PRO1005TCometic Street Pro Kits are geared toward the street rider who is looking to purchase a kit with all necessary gaskets and seals needed for your rebuild.... Cometic Street Pro GM 1970-85 454ci Big Block 4.375 Top End Gasket Kit 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $220.59 |
 SHIPS FROM MANUFACTURER C15283Cometic Chevrolet Mark-IV GM Gen-V/VI Big Block V8 Timing Cover Seal 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $45.87 |
 SHIPS FROM MANUFACTURER C5053Cometic Chevrolet 153 4 Cylinder Gen-3 Inline 6 Timing Cover Gasket Kit 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $47.31 |
 SHIPS FROM MANUFACTURER C5057Cometic Chevrolet Mark-IV GM Gen-V Big Block V8 Timing Cover Gasket Kit 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $49.15 |
 SHIPS FROM MANUFACTURER C5345-031Fully cured nitrile butadiene rubber binder for maximum fluid resistance... Cometic Chevrolet Mark-IV GM Gen-V Big Block V8 .031in Fiber Timing Cover Gasket 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $54.19 |
 SHIPS FROM MANUFACTURER C5377Cometic Chevy Mark IV Big Block V8 Timing Cover Seal Jesel Belt Drive Dual Lip Wet & Dry Sump 86622 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $93.46 |
 SHIPS FROM MANUFACTURER C5381Cometic Chevy Mark IV Big Block V8 Rear Main Seal 2 Pc Double Split Seal Wet & Dry Sump 86665 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $113.32 |
 SHIPS FROM MANUFACTURER C5650Fully cured nitrile butadiene rubber binder for maximum fluid resistance... Cometic Chevrolet Mark-IV GM Gen-V Big Block V8 .031in Fiber Timing Cover Gasket Kit 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $55.91 |
 SHIPS FROM MANUFACTURER C5650AFMA chemically blown, compounded, nitrile synthetic rubber bonded to an aluminum core... Cometic Chevrolet Mark-IV GM Gen-V Big Block V8 .032in AFM Timing Cover Gasket Kit 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $55.91 |
SHIPS FROM MANUFACTURER CP15283Cometic Chevy Gen-4/5/6 Big Block V8 Timing Cover Seal - 10 Pack 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $80.82 |
 SHIPS FROM MANUFACTURER CP5345Fully cured nitrile butadiene rubber binder for maximum fluid resistance... Cometic Chevy Gen-4/5 Big Block V8 Timing Cover Gasket .031in Fiber - 10 Pack 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $75.55 |
 SHIPS FROM MANUFACTURER PRO1003T-400-040MLS Gaskets are comprised of multiple embossed layers of both AMP (Advanced Multi-Polymer Coating) and uncoated stainless steel... Cometic Chevy 350 Gen1 Small Block V8 Top End Gasket Kit-4.000in Bore-.040in MLS Cyl Head Gasket 1978-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande / Street Coupe $290.62 |
 SHIPS FROM MANUFACTURER PRO1003T-4020MLS Gaskets are comprised of multiple embossed layers of both AMP (Advanced Multi-Polymer Coating) and uncoated stainless steel... Cometic Chevy 350 Gen1 Small Block V8 Top End Gasket Kit-4.020in Bore-.040in MLS Cyl Head Gasket 1978-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande / Street Coupe $290.62 |
 SHIPS FROM MANUFACTURER PRO1003T-4060-027MLS Gaskets are comprised of multiple embossed layers of both AMP (Advanced Multi-Polymer Coating) and uncoated stainless steel... Cometic Chevy 350 Gen1 Small Block V8 Top End Gasket Kit-4.060in Bore-.027in MLS Cyl Head Gasket 1978-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande / Street Coupe $290.62 |
 SHIPS FROM MANUFACTURER PRO1003T-4060-040MLS Gaskets are comprised of multiple embossed layers of both AMP (Advanced Multi-Polymer Coating) and uncoated stainless steel... Cometic Chevy 350 Gen1 Small Block V8 Top End Gasket Kit-4.060in Bore-.040in MLS Cyl Head Gasket 1978-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande / Street Coupe $290.62 |
 SHIPS FROM MANUFACTURER PRO1003T-4060-062MLS Gaskets are comprised of multiple embossed layers of both AMP (Advanced Multi-Polymer Coating) and uncoated stainless steel... Cometic Chevy 350 Gen1 Small Block V8 Top End Gasket Kit-4.060in Bore-.062in MLS Cyl Head Gasket 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half $267.04 |