Description: This is a pair of original GM cylinder heads for a Big Block Chevy Engine. The casting number on each head is 3964291. These heads are the high performance version with rectangular intake ports and closed combustion chambers. These heads were used by GM on late 1969-1970 L78 396/375HP, Late 69 L71 427/435HP, and 70 LS6 454/450HP engines. These heads were also used as a direct replacement for casting numbers 3856208, 3873858, 3904391, and 3919840. What a rare find! These heads are in very nice condition. These heads were purchased for a 1970 LS6 454 that was to be installed in a 1970 Chevelle convertible. The car was sold to a buyer looking to install a late model drivetrain. I bought the LS6 shortblock, these heads, intake manifold, carb, and other parts. Don't miss this awesome set of heads. As stated above, these heads were bought by the prior owner for a 1970 LS6. He bought these heads as freshly rebuilt and he kept them oiled and bagged up until I recently bought them. The heads have no porting on the intake or exhaust ports. The valves look to be 2.30 inches on the intake and 1.88 inches on the exhaust. The valve springs are new LS-6 spec units. The chambers look very nice with one professionally repaired area in a chamber and another at a cooling port on the deck surface on one head as shown. The threads all look usable with no helicoils or thread inserts. The exhaust threads do show wear and all hold a bolt well. These heads are dated L 8 9 and L 9 9 which decodes as December 8th and 9th, 1969. That's right, this is a true 1970 production year dated pair of heads. This is your chance to own awesome factory matched pair of HI PERF Big Block Chevy heads for your special engine or collection at a great price. Don't Miss Out! Check out my other listings for more rare and hard to find parts. The shipping cost shown is for the continental US. Alaska, Hawaii, and territories please inquire for a shipping cost.
Price: 1950 USD
Location: Santa Cruz, California
End Time: 2025-01-05T01:41:33.000Z
Shipping Cost: 189.85 USD
Product Images
Item Specifics
Restocking Fee: No
Return shipping will be paid by: Buyer
Returns Accepted: Returns Accepted
Item must be returned within: 30 Days
Refund will be given as: Money Back
Brand: General Motors
Interchange Part Number: 1968 1969 1970 1971 68 69 70 71 Chevy Chevrolet COPO Yenko, Nova SS RS Super Sport fout bolt mains caps 964 LS6 LS-6, L88 l-88 L71 L-71 L72 L-72 512 425HP 435HP 450HP 1965 1966 1967, CE Counter Exchange warranty replacement Number numbers matching, baldwin motion nickey dealer installed hot rat rod period correct, racecar race car day 2 two vintage speed shop solid lifter cam, 3910 3933163 3933198 3963569 aluminum intake 3885069 3919840, Camaro Chevelle Nova Impala Corvette BBC rectangular rectangle, square hi perf LS6 LS-6 L78 L-78 396 tri power 3x2 intake, 3904391 3904392 3856208 3873858 7115 crank crankshaft 7416 6223, 291 840 closed combustion chamber chambers
Vintage Part: Yes
Performance Part: Yes
