4.2 heads on a 3.8?

[LoganB]

I briefly heard about this and I’d like to understand it a bit better. I don’t really plan on doing it anytime soon if it ends up being a good mod since I don’t hav the money yet. I heard that the heads off of the 4.2L are virtually the same as the ones on the 3.8L. I also heard that they’re just straight bolt on to the engine. I read that they’re stronger heads but could lower your compression a tad bit. There’s just a few things I would like answered.

What would be the benefits of doing this? Any significant power gains? Airflow? Cooling? Reliability?

Have any of you tried this out yourselves? If so, what was your reason and how did you go about doing it?

What else would you pair it with? I imagine that this paired with some form of forced induction would work good, but what else?

Other than that I guess I’d be curious about how expensive a mod like this costed you (if you’ve tried it) and what kind of power you were pushing after it all.

Again this is just my curiosity since I briefly got told about this at work the other day and wanted to see if anyone had tried it

 

[KevinVarnes]

I believe the 4.2 heads are the same or similar to the 3.8 split port heads. Seems like the Mustang 3.8 split port heads and intake with a 4.2 bottom end would be a pretty good combo if you stayed V6. I'm sure there is a ton of information out there if you search for split port head swap or something like that.

 

[MadMikeyL]

The 4.2 was only available as a split-port motor. All the split-port heads are the same, regardless of whether they were on a 3.8, 3.9, or 4.2. Running the split-port heads requires the matching split-port intake manifold, either from a Mustang, or a Windstar. Externally, the 3.8 and 4.2 engines are identical, except for the intake manifold, so if you were looking for more power, your best bet would be to buy a complete 4.2, and a Mustang intake manifold, and swap out that setup for your existing 3.8.

 

[1997ThunderbirdLXV6]

I find it funny how anytime the split-port conversation comes up, inevitably someone utters the word "Windstar". Such a turn-off. I mean factually correct, but still...ew.