this is an ancient thread and I just joined but here goes anyway. Very early 66 428 Pi engines came with solid tappets, they used an identical cam to the c3ae-AA 427 cam except with no oil grooves. The intake was an aluminum with casting numbers C6AE-9425-E, I believe later replaced by C6AE-9424-H. Another oddity is due to the adjustable rockers and .500 lift cam they installed painted pentroof 427 style rocker covers. Later in the year they went to hyd lifters and a cam with less lift and duration along with an HP drop from 360 to 345. This is based on personal experience as well as things I have now and have seen in the past, good luck, Tim
John Smith's book: "Super '60s Fords" says on P.58:
"The largest displacement engine in the 1966 Ford lineup was the new 428cid 4-barrel Police Interceptor 7-Liter V-8, with 360 horsepower at 5400rpm, 459 lbs-ft of torque at 3200rpm, 10.5:1 compression ratio, hydraulic valve lifters and a single 780cfm Holley 4-barrel carburetor on an aluminum intake manifold. The entire engine was dark "Ford blue" in color. Replacing the old 390 P.I. engine, and supposedly available only to law enforcement agencies, Fords originally equipped with this engine carry the "P" engine code on the data tag."
BUT, you can take that with a grain of salt, for he also said on P.33:
"As in the previous three years, the Police Interceptor continued to be available for "law enforcement" use. The PI 390 featured 330 horsepower at 5000rpm, 437 lbs-ft of torque at 3700rpm, with a 10.1:1 compression ratio, high-lift mechanical camshaft, and a single 600cfm Holly 4-barrel carburetor on an aluminum intake manifold. The engine block and cylinder heads were black in color, with gold valve covers and air cleaner. Fords originally equipped with this engine carry the "P" engine code on the data tag."
The above paragraph has two "glaring" mis-statements:
1. I have a 1964 Ford Galaxie 500, Four-door, Hard-top, Fast-back, Police Interceptor and it came with a CAST IRON intake manifold.
1964 FORD GALAXIE 500 PI
2. Although it has a Holley 4150 650cfm carburetor (put on as an after-market item), it originally came with an Autolite 4100 1.12 C3AF 9510 (with various suffix letters such as BY, BU, and BZ, depending on the kind of transmission). The Holley will soon be replaced with an Autolite 4100 1.12 C4AF 9510 DG, which has just been restored.
Autolite 4100 1.12 C4AF-9510 DG Carburetor
What we NEED around here is someone with a 1966 PI that hasn't been molested. That would solve the mystery!
Hope you are well.