4.6 Heads & Valve Covers
 

I am new to these motors - some help would be appreciated.

I have 2 versions of 4.6 motors: a 94 (supposedly PI, but not really sure as I know it was swapped out at one time) and a 2000 Mustang with PI Heads.
When I bought the Mustang I thought that they normally came with the PI heads (Know they are PI because of the casting ID). Now it turns out that maybe they are not normal. (PI = Police Interceptor)
I have been trying to obtain a new valve cover for the one with a broken oil fill tube without success. The set I bought recently was suppose to fit Mustang GT 96-2001, but they appear to be more like the earlier type (i.e. 94).

What I have is 2 different bolt patterns on the covers: the earlier one has 11 in all; 5 along the top and 6 along the bottom all pretty much in a straight line. 2 are in front of the cam gear hump. Kind of like the diagram below.
o o o o o

o o o o o o

The newer one has 14 in all; 6 along the top, 6 along the bottom, and 2 in front of the cam gear hump. The front 2 are displaced toward the center-line of the head from the rest. And the rear-most one on the top is offset from the line further up a little. Kind of like the diagram below.

o
o o o o o
o
o
o o o o o o

Does anyone out there know whether the newer one is completely unique to the PI heads or is it common to the Mustang GT 4.6 or something else entirely?

Oppps!
 

The second diagram dosen't show as it did when I created it.
Try again... Ignore the dashes.
o
o o o o o
----------------------o
----------------------o
o o o o o o

Oppps Again!
 

The second one doesn't look right either. Try once more. Again, ignore the dashes; I need them to get the proportions right.

-o
-----o----o----o----o----o
-------------------------------o
-------------------------------o
-o----o----o----o----o----o


:D

94 gt's still had the 302 ci 5.0L v 8....the 4.6 didnt debut until the '96 model year...hope this helps!

or do you just a 94 model 4.6 L motor from another vehicle?

if I remember correctly there are two sets of heads, One is the windsor heads and the others are romeo heads. the romeo heads have eleven bolts and the windsor have twelve. Cant remember exactly but I belive the romeo heads are the better set of heads. This came out of a 5.0 mustang mag from about three months ago that explained the two head types. IE - same engine but two different valve cover bolt patterns.

Hope this help, my memory isn't the best!!

Clarification
 

We are talking about a retired Police Car here - a '94 Crown Vic.
The new motor is out of a 2000 GT with PI heads (that's the way it came). It came with no fuel system so I adapted the 94 fuel system to the heads. Same manifold bolt pattern but very different gasket setup. Old gaskets worked once I removed the locator pins. The old manifold ports are bit smaller but have the same general shape. Runs like a scared rabbit.

you'll want to get a 99+ intake manifold as it is different and flows a lot better then that 94 piece you have.
All Mustang 4.6's got the PI heads starting in '99. The '94 4.6 has the old style heads (eg: don't flow well) and the police interceptor motors had no differences between the street version. '94-'98 & '01+ 4.6 2V's all use the same style valve covers, while 99-00 use a different pattern.