351c 4v heads on a 351m? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

dlone · 10-16-2010, 15:54

will 351c 4v heads fit on a 351m?

Rapid_Roy · 10-27-2010, 16:52

yes

Mach1steve · 12-02-2010, 10:45

Yes they will, but you need to do some adapting for the water cooling holes on the head gaskets, and buy a special intake to fit specifically made for this adaptation.

A 351W with 351C heads is called a Clevor

Here's a good link with lots of info for you.....
The Mustang Shop - Building a 'Clevor' Engine, Cleveland heads on a Windsor block

Let us know if you do it

cobra269au · 12-03-2010, 17:56

Hi dlone,
4V Cleveland heads will fit on a 351M (Midland) engine, but the ports are very much larger than the 2V ports in the 351M heads. I am not aware of any manifold produced to fit this combination, and while the 2V manifold will fit, the port size mismatch couldn't make this a great selection.
Can I ask, "What are you trying to achieve with this swap?"

George1861 · 12-03-2010, 18:09

Quote:

Originally Posted by Mach1steve

Yes they will, but you need to do some adapting for the water cooling holes on the head gaskets, and buy a special intake to fit specifically made for this adaptation.

A 351W with 351C heads is called a Clevor

Here's a good link with lots of info for you.....
The Mustang Shop - Building a 'Clevor' Engine, Cleveland heads on a Windsor block

Let us know if you do it

It's an M, not a W!

George1861 · 12-03-2010, 18:12

Quote:

Originally Posted by cobra269au

Hi dlone,
4V Cleveland heads will fit on a 351M (Midland) engine, but the ports are very much larger than the 2V ports in the 351M heads. I am not aware of any manifold produced to fit this combination, and while the 2V manifold will fit, the port size mismatch couldn't make this a great selection.
Can I ask, "What are you trying to achieve with this swap?"

There's been a number of "Engine Challenge" entries lately based on 400s with C heads. But the C heads are supposed to flow better, even the 2V C.

Khyren · 02-15-2011, 21:31

Well, depends if you are using the 4V open or closed chamber design heads. The closed chamber ones will up the compression to the point that you are going to have to run race gas. Somewhere in the neck of 11.5:1 with the stock pistons because of the stroke and reduced CC size. I can't remember if the exhaust manifolds will even bolt up to this or not. The last ones I heard were using a 4V 351C intake with some machined spacers because the M block is wider. So they have to take the C intake up and center it with spacers to make the intake ports work. Also, finding a good set of 4V closed chamber heads is getting really rare. I had an Australian buy mine off me if that tells you how hard they are getting to find. You'd be better off just getting a set of the edelbrock aluminum heads and call it a day since they bolt right on and compression will still be tolerable.

George1861 · 02-16-2011, 03:13

Quote:

Originally Posted by Khyren

Well, depends if you are using the 4V open or closed chamber design heads. The closed chamber ones will up the compression to the point that you are going to have to run race gas. Somewhere in the neck of 11.5:1 with the stock pistons because of the stroke and reduced CC size. I can't remember if the exhaust manifolds will even bolt up to this or not. The last ones I heard were using a 4V 351C intake with some machined spacers because the M block is wider. So they have to take the C intake up and center it with spacers to make the intake ports work. Also, finding a good set of 4V closed chamber heads is getting really rare. I had an Australian buy mine off me if that tells you how hard they are getting to find. You'd be better off just getting a set of the edelbrock aluminum heads and call it a day since they bolt right on and compression will still be tolerable.

2V & 4V ex mans don't interchange, even on the C.