Question about 454 and 427 heads (Chevy heads: casting them and bolting them, etc.)

[Soul Reputation]

I have a friend who needs a little advice. His computer skills are limited, and so he asked me to help him out by creating this post.

He has two questions.

1) What are the differences in casting (or anything) on a 427 Chevy big block head?

2) And can he bolt a 427 Chevy head on to a big block 454 Chevy?

The questions are in his words, not my words (I'm not a car guy).

Question-wise, that is all the information that I have.

Even though I'm not a car guy, I kinda get the feeling that you might need to know more info, as if the questions are a little open-ended and lack details.

If that's the case, then let me know what you need to know and I'll contact him on your behalf.

I'm not entirely sure, but I tend to think the questions are not be related to a car. He lives on a yacht. He's not Donald Trump, not even close: The yacht is an older yacht.

Perhaps the Chevy blocks power the yacht? Maybe...

If you believe in karma and you are able to help, then you might have some karma coming your way. He's a single father who, for many years, was raising two kids on his own.

Now he's down to one child.

His 14 or 15 year old daughter was murdered not long ago.

Hey, thanks in advance for any help you can muster up

 

[foghorn67]

Sorry about your friend's loss.
Anyway, what years are the block and heads?
-edit-You're biggest hurdle will be open vs. chambered heads.

 

[Soul Reputation]

Sorry about your friend's loss.
Anyway, what years are the block and heads?

I asked and he said

"1984, they're generation-4...454 Chevy with oval port heads."

I don't know if that makes sense or not. He's a wrench guy I'm not, all that stuff is foreign to me.

 

[Meghan54]

Head over to iboats.com and ask there. GM power plants for marine use, while almost identical to the land-based power plants, aren't exactly the same, esp. with the differing fittings/manifolds/etc. for the cooling. There may be some peculiarities specific to the GM boat engines that most of us don't realize.

 

[Pacfanweb]

A 427 and 454 Chevy use the exact same block, so the heads for either motor will physically bolt right on, if they're the same vintage.

Now you have to know about the pistons and whether he needs open or closed chamber heads. Unless it's a pretty old motor, probably open.

If it's not stock, then we'd need to know about his pistons.

But in general, they will interchange.

 

[Pacfanweb]

I asked and he said

"1984, they're generation-4...454 Chevy with oval port heads."

I don't know if that makes sense or not. He's a wrench guy I'm not, all that stuff is foreign to me.

Just saw this after my first post. He probably means "Mark IV", so any Mark IV oval port heads will work.

That means all heads up to 1990 will work. If he has oval port heads, he needs to use oval port heads unless he changes the intake manifold.

 

[Bartman39]

Ok as for open chamber heads fitting on closed chamber pistons then yes they will work this is a fairly simple setup... But of course you get the loss of compression factored in to this situation as well...

But as for closed chamber heads fitting on open chamber pistons then no they will not work in this situation... Also in addition to this situation the Gen 5 heads and pistons do not work with either the Gen 4 or Gen 6 heads and pistons... Some Gen 6 stuff will work with the Gen 4 but not much the Gen 6 stuff is kinda to its own but some does fit...


Ok as an answer to your original question in most cases the answer is NO the 427 head will not fit on to the 454 piston (closed chamber Vs. open chamber)... Now the other way they will fit but compression my become rather difficult to figure...?

The main difference is in the heads themselves the earlier 427 heads were made for closed chamber pistons while the later 454 heads were made for open chamber... There is a lot of difference between these heads even though they are somewhat a like...