3964291 Heads Big Block Chevy Rectangular Port Late 69-70 L78 396 L72 427 LS6 454

[SuperNovaSS]

This is a pair of 3964291 heads. The 3964291 heads were used on late 1969-1970 L78 396/375HP, 69 L72 427/425HP, 69 L71 427/435HP, and 1970 LS6 454/450HP engines. They were also replacements for all other BBC cast iron rect. port closed chamber heads.

These heads have been in storage since the early 70s and are in very good condition. There is no porting or other modifications. There is no damage or repairs. All guides seem nice and tight. All threads are in good shape with no helicoils or thread inserts. The valves are 2.19 inch intake and 1.72 exhaust. The deck surfaces on both heads are nice and thick. The heads are dated A 20 70 and E 7 70. I can't imagine finding a nicer pair of original castings. The heads came to me disassembled. I just put them back together less the valve stem seals. The heads should be rebuilt before being used.


$1350 plus shipping.


Thanks,

Jason

[WILMASBOYL78]

They look great..GLWS.

?? I thought all 291 heads had the 1.88 exhaust valves ??

-wilma

[SuperNovaSS]

I thought they all came with 1.88 valves as well. Possibly not service replacements since the 291 heads superceeded early heads. If someone just needed one head under warranty, they would need a head with 1.72 exhaust valves. I imagine these were bought new over the counter and they installed the 1.72 valves out of the other heads that had issues? Its really all speculation at this point. These heads came off a 427 that was in a 69 Nova. Since these heads have 1.72 exhaust valves, I imagine they would be good for pure stock racing on earlier engines since they are completely stock.



Jason

[SuperNovaSS]

Heads are sold.


Thanks,

Jason