How much potential does the HA heads have

[kad5118]

In the future I do plan on rebuilding my 3.8 carb turbo engine.I want to reuse the stock carbed hot air turbo heads that came with the engine.I always hear about the 86 87 heads as being able to support good power in there stock form and port and polished job as well.But what about the 78 - 82 carb hot air heads.can they put out decent power.

 

[ek02]

The only difference I see in the late 8445 heads and the early heads is the bridged water passages front and rear, and the rocker stands. The 8445's are less prone to blowing the head gasket between the water passage and the cylinder. The rocker stands are a little beefier on the 8445's. There may be more differences, but that is all I can see.

 

[kad5118]

The only difference I see in the late 8445 heads and the early heads is the bridged water passages front and rear, and the rocker stands. The 8445's are less prone to blowing the head gasket between the water passage and the cylinder. The rocker stands are a little beefier on the 8445's. There may be more differences, but that is all I can see.

which ones are the 8445's

 

[ek02]

86-87 are casting #8445. The 4.1 also came with those heads from about 82 up. Earlier years may have 8445's also, but I am not sure. I have had both 8445 and 293 heads. The ports are the same. No power advantage to either one that I can see, just the reliability of the head gaskets at the front and rear and the beefier 8445 rocker stands. Anyone else see any differences?

 

[WarWagon]

'84 and later 3.8/4.1 have 8445 casting heads.

 

[ek02]

WarWagon, I saw your blown head gasket on your Repeat Procedure thread. They always blow there, especially with the old 293 heads without the bridged water passages. What heads were you running?

 

[WarWagon]

Ohh yes I know that I've blown my share of head gaskets with 293 casting heads, before going to 9441PT gaskets and 8445 heads.
Those are the factory GM steel shim gaskets on my 140 casting block ('85, 20 bolt pan) it had the factory 8445 heads too. The gaskets actually did not fail from any combustion events just 29 years of corrosion on them.

 

[ek02]

It's always been a weak spot. Smokey Yunick welded the block together in the front and rear in the early days of the V6 to prevent it. I think kad5118 could make the same power with the 293 castings as the 8445, but for reliability, the 8445 would be a better choice if they could be had cheap. In some parts of the country where they are still in the junk yards, a $100.00 to $150.00 could get a pair.