OEM GM Big Block Chevy Aluminum Cylinder Heads 3946074 L88 ZL1 Rectangular Ports

[SuperNovaSS]

This is a pair of original GM high performance aluminum cylinder heads for a Big Block Chevy Engine. The casting number on each head is 3946074. The 3946074 heads were originally developed for the second design 1969 L-88 engine and 69 ZL-1 all aluminum 427 engine. These were also used by Chevrolet on the 1971 Corvette LS6 which these heads are dated to. These heads are the high performance versions with rectangular intake ports, open style combustion chambers, and round exhaust ports. The 3946074 head was also optional on the infamous LS-7 454 crate engines and was also a very popular performance head in both automotive and marine applications. What a rare find!

These heads just came out of the estate of a hot rodder and performance enthusiast. He pulled these off a running jet boat in the early 80's and they have been in cool ,dry storage ever since. These heads are in good condition overall. The heads are complete as they were pulled off the boat with valves, springs, retained, guide plate and studs intact. I see no breaks or repairs to these heads. All rocker studs are in great shape, not broken and welded like many you will see. The heads also have no corrosion in the cooling ports or else where. In intake and exhaust ports are completely stock with no porting. All threads are in good condition with professionally installed helicoils in the exhaust threads and a few intact threads. As you can see, they have been polished on the externals and there is just enough of a Winter's snowflake casting on each head to let those in the know in on the secret of what these are. Each head also had a port drilled on one end as show for use on the jet boat. These could be welded closed easily since these heads are aluminum. The deck indicators on the outer corner of the deck surface of each head are quite thick showing these heads has not been significant surfaced or "decked" like mast you will see that no longer have this indicator at all. The combustion chambers are stock with many nicks from ingesting some foreign material in the past. These nicks could be welded and contoured to look pretty but the heads are functional as they are and have been run this way. These heads have been in storage for decades and should be rebuilt before use.

$2150 plus the ride


Thanks,

Jason