What heads are interchangable with a '78 Turbo?

[Hit Man X]

What model year heads do I need to look for?

Thanks!

 

[b4black]

The V6 heads were completely resigned for 1977 and the ports enlarged in 1979. So you are limted to 1977 - 1978 heads.

Many '78 owners swap over to '79-87 heads, but this would require a '79 or later intake and exhaust manifolds.

 

[Freddie's Buick]

If you find an '81-3.8 engine the heads are 25506293 or later. Find the cast number under the valve covers on the heads. And as Rich pointed out, you will have to use the later exhaust manifolds or headers. You can find this info in Pat Ganahl's book, 'V-6 performance' on page 82.

 

[Hit Man X]

So, if I got some 81 heads, can I get N/A heads?
Will '83 headers work with it?
I'll have to use the later intake too?

 

[b4black]

The heads on a Turbo V6 and a NA V6 are the same.
The heads from 1979-1987 RWD engines are the same (some minor casting changes).
1983/85 exhaust manifolds will fit all 1979/87 heads(1979/80's manifolds may be more durable.)
That leaves the intake - you would want a '79 to keep things similar to your '78.

 

[Hit Man X]

Okay, let's see if my dumbass understands:

83-85 exhaust manifolds will work on any 79-87 heads?
If I use 79 heads I can keep my intake manifold?
If I use 80+ heads I have to get the matching intake manifold?

Didn't the manifolds change from cast iron to aluminum?

 

[b4black]

Originally posted by Hit Man X
Okay, let's see if my dumbass understands:

83-85 exhaust manifolds will work on any 79-87 heads?

YES.

If I use 79 heads I can keep my intake manifold? If I use 80+ heads I have to get the matching intake manifold?

There are 77-78 heads and 79-87 heads. If you use your '78 intake on a '79 (or later) head, there will be a port mistmatch.

Any 79-87 intake will fit any 79-87 head. If you changed heads, the best choice would then be a 1979 intake. It will have the correct ports for the new heads, and be the most compatible with your '78's emissions (EGR, vacuum lines, plenum coolant, ESC/knock sensor, etc.).

Didn't the manifolds change from cast iron to aluminum?

Yes, in 1980 they became aluminum. You could use a '80 (or later) intake, but you would need to relocate the knock sensor from the intake to the block, which reqiures drill and tapping a hole.



I hope I was a little clearer this time.

 

[Hit Man X]

How hard would it be to find a '79 intake?

And I could use any heads from 79-87 that will: work with the '79 intake and 83-85 manifolds?

 

[b4black]

And I could use any heads from 79-87 that will: work with the '79 intake and 83-85 manifolds?

This combo would work.

'79 motors are fairly common. You might find a complete motor before just an intake. I would go that route and use all the '79 parts on your '78 short block.