police interceptor heads

I have a 1967 Cougar, and I just purchased a 428 Cobra Jet to put in it. The Cobra Jet has Police Interceptor heads, which is a concern to me due to the fact that they have only 8 bolts on the manifold. I know this will be an issue to get to them because of not having the typical CJ 16 bolts. I am wondering if anyone else on this forum has tried this and had success at putting in a big block with Police Interceptor heads and being able to get the manifolds on and tight. Do they make headers that would work? I don’t want to switch to CJ heads unless totally necessary. Any help or suggestions would be greatly appreciated.

Yes, you can use them, just not with so-called GT exhaust manifolds. What’s the engineering number on the head between the two center plugs? The loss here is really horsepower. PI- C7AE-A or C8AE-H heads are low performance heads with standard FE valves and ports. It’s not a cobra jet unless it has the CJ heads. It’s a 428. CJ’s also come in 14 and 16 bolt pattern variants.

The PI heads can be drilled and tapped to the 390GT exhaust manifold bolt pattern. The '67 GT500 used a 428PI engine with 390GT manifolds, so this combination will fit your Cougar. It’s just not the most effective set up from a horsepower standpoint.

You can’t drill them on the engine. Don’t try. I don’t imagine you’re planning on pulling the top end. If they are the so-called GT heads the front and rear bolt hole on the top of the exhaust flange is lower, which creates it’s own issue with manifolds. We should be able to shed a lot more light with the engineering numbers. On the back of the block is there an A scratch or a C scratch?

On 69 and 70 PI C8AE-H heads the H will have been partly ground off during build up. aI understand this is to indicate the head was built to whatever the PI speck was. My 70 PI has one original head and this is how it is. The other head is a D2TE head. Basically the same but with hardened valve seats.
One of the funny things about a 70 CJ and a 1970 PI is how Ford lied about Horsepower and torque.
Police Interceptor 360 hp @5400 459 ftlb @ 3200 Maybe…
Cobra Jet 335 hp @5200 440 ftlb @ 3400 Fake news.
I do have the C8OE-N heads for my 428. I’m really looking forward to stomping in the loud pedal when I get it running.

They can be drilled and tapped on the engine, but that’s not an easy task. It requires a lot of skill, and at a minimum the engine needs to be out of the car.

If you bought a 428 Cobra Jet it has very specific cylinder heads with either the casting number C8AE 6090-J (before February 1968) or C8OE 6090-N (after February 1968). If the engine does not have Cobra Jet heads it is not a Cobra Jet 428. The short block used on a 428 PI engine built after August 1967 is identical (except camshaft) to the short block of a 428 Cobra Jet. Every 428 engine after August 1967 has the identical parts whether it is a 428CJ or the 428 in a cop car or the 428 in Granny’s Mercury station wagon.

The heads are a C8AE that I can see, but there may be more. This is a 1969 428 CJ cast C block, the real deal, with correct CJ intake on it, crank, and just the heads that are different on this motor. I got a great deal on this motor, which has been rebuilt. This is a complete CJ motor, just had heads changed to PI heads. I currently have a 351 Windsor in my '67 Cougar, but I simply couldn’t resist the deal for this 428 CJ. I know the best route would be to put CJ heads on it, but I am really hoping I can use it with the PI heads.

The C scratch blocks replaced the A scratch blocks during August 1967. After some period of overlap where either might be used, all 428 engines used that block. And all of them used the 1U crankshaft, and C7AE-B connecting rods. The 428CJ used a slightly larger rod bolt that is 13/32" diameter, which is an easy upgrade for the regular 390 / 428PI rods if desired.

The PI and the Cobra Jet 428 both used the identical cast iron 4V intake after December 1968. So no, I am sorry, you don’t have anything that sounds like it is a Cobra Jet, because it is missing the only Cobra Jet specific parts - the cylinder heads and exhaust manifolds.

PI cylinder heads sometimes have only the C8AE with the H ground off. Other times they only have what seem to be ordinary C8AE-H heads. These low performance heads combined with the restrictive PI exhaust manifolds cost ~ 50 - ish horsepower compared to the correct 428CJ heads.

This might help you:


Royce knows it’s a bad idea to drill them on the engine. There are several reasons why when they are done, they are done off the engine. You can’t do them in the car, period. The hole location has to be exact. The angle has to be exact and depth has to be controlled. Absolutely not for an amateur because they think they can match the holes on a gasket. This is As I mentioned: You are less 60HP. What do you know about the build? Receipts? Cam information?
Far too many times have I seen a so-called engine be labeled a rebuild and they slapped rings and bearings and new lifters on an old cam with a gasket set.
Because of the work involved in the change over and it’s cost and time I highly suggest if there aren’t receipts for parts and that of a professional builder you at minimum should pull it back down to a short block to see what you have.
You may look a this as a gloom and doom scenario but it’s pure wisdom. If you’re going to run headers you can simply run the Hooker 6114 headers. They will work with the bolt pattern as is. The center bolts under the headers are your only real difficult ones.
The engine can be installed with the headers, but the vehicle has to be high up on jack stands in the rear and the idler arm unbolted and wheels turned hard right. I’ll be glad to share pictures if you’d like. What trans is going in? There are a slew of changes and different parts required for a change to an FE. It’s not just the block plates and engine insulators.