3919842 Aluminum Heads 396 427 L88 Closed Chamber

[SuperNovaSS]

This is a pair of original GM aluminum cylinder heads for a Big block Chevy engine. The casting number on each head is 3919842. The 3919842 heads were originally used by GM on the following applications: 1968-70 L-89 396/375HP, 1968-69 L-89 427/435HP, and 68-Early 69 L-88 427/430HP engines. These heads were the top dogs of their day. Very few were ordered since the options were very expensive for the time. Finding a set of 3919842 heads today is a difficult task. Finding a set in very good condition like the set you are looking at now is near impossible.

These heads are in very good condition as shown. As mentioned above, these were the most high performance head of the time when they were introduced, including aftermarket sources. If you wanted aluminum heads for your big block, you went to GM. Most of these heads were sent to a performance shop and ported and modified from the first day they were used. Even more later encountered high lift cams and broke rocker stud bosses which will never be the same again. Others suffered valve clearance issues, etc that iron heads would survive but aluminum heads would not. Even more fought the battle of corrosion and lost. Finally, when the open combustion chamber heads were released, many of these closed chamber heads were poorly converted to the open chamber design. While these heads have had some small modifications to aid in performance, they have survived the test of time and will look 100 percent original when installed.

These heads are in very good original condition. All part numbers, markings, and winter's foundry snowflakes are intact and undisturbed. There are no breaks or repairs. There is also no corrosion on these heads. All rocker stud bosses are in great shape. The chambers are still the closed chamber design and have had the valve unshrouded which will help the flame pattern while cutting the compression down a bit. One chamber has some nicks on the flat areas from some kind of debris that got in the cylinder, no biggie. The heads have not been heavily decked/surfaced as evidenced by the thick deck indicator on the outer corners of the underside of each head. All threads are excellent with NO helicoils of thread inserts other than those for the rocker studs which were installed by GM. The ports are very nice with deburring on the intake ports and some porting on the exhaust. The heads have the valves, springs, retainers, locks, guide plates and rocker studs intact and simply need your rockers. These heads were rebuilt decades ago and have been installed on a sealed 427 engine that was never started. They are likely OK to install as they are but taking them apart to inspect and lube them would be a good idea. These 3919842 heads are getting almost impossible to find in any condition. This is a very nice set that won't kill the budget.


SOLD


Thanks,

Jason

[napa68]

What are the dates Jason?

[SuperNovaSS]

They don't have any dates and there are no plugs on the ends. They are likely mid 70s.


Jason

[737Driver]

842 with no casting plug(s) began in the spring of 1969. There should be a casting date in a runner.

[69 Post Sedan]

Jason is correct....these are OTC heads. If you look at the bottom on one of the heads, it has a 05010, that is the casting date but I've never really figured out how to decode it. If I were to guess, I would say it is May, 1st of 1980......but that is just a guess.

163 intakes were cast the same way during that era.

Hope that helps, Kurt

[SuperNovaSS]

Sold.

Thanks,

Jason