3.8 intakes on a 4.2L head?

I’m backdating a 4.2L to use in a D-type project.
I’m looking into a triple 4D8 SU setup from a 3.8L vehicle.
Would the intake be interchangeable with the 4.2 head?
Are there any pitfalls with this idea?

I appreciate any and all help.


Sorry guys, now that I’m in the shop and looking at the head I see the additional jackets.

The coolant ports on the head are blocked with brass hex plugs on the 3.8.

Most 3.8 have a B-head, only early 3.8 E-types had Straight port heads.
They do not interchange, as all 4.2’s have SP heads.

Am I Confused?

I really appreciate the input,
I like the plugs as a solution. Is there any down side?

Nope: just make sure to use thread sealant, and tighten them properly.

For all those looking for the answers… the passages on my cylinder head were 1-5/64". The Melling part number is MPC-174.

Stay thirsty my friends.