Technical 428 Police Interceptor Motor questions

[falcongeorge]

PI's are kinda like the the FE equivalent of "corvette motor". Probably a 410, not that that is a terrible thing just dont pay PI $$$. Take a magnet, see if it sticks to the intake.

[George]

Originally Posted by 36cab

I believe Shelby changed the name to GT500KR when he started putting the 428CJ's in them.

The KR was a normal 500 with a differnt decal on it. Shelby heard that Chevy was going to call a version of the Vette "King of the Road", so he had some GT-500 KR decals made up & stuck em on a number of cars in assembly. Admitted a few years ago that they are standard 500s.

[hoop98]

I'm pretty sure the KR's were the CJ's

"
The 1968 Shelby Cobra GT 500 KR
King of the Road
by Dennis Begley

Ford offered the Cobra Jet engine for the first time in 1968 1/2. Carroll Shelby, always one to up the competition, be it Ford or GM, put the 428 CJ engine in his GT 500 Shelby Mustangs about two thirds into the model year. It was cheap horsepower. Early '68 GT 500's were given Ford's 428 police interceptor engine. Rated at 360 hp at 5400 rpm, the big block produced 420 ft. lbs. of torque at 3200 rpm. Mid-year, Shelby got wind that GM intended to introduce a 396 Camaro and call it "King of the Road." Shelby beat them to it. Before GM could follow through, Shelby American offered a GT 500KR, King of the Road and stuffed the Cobra Jet engine under the hood.
The 1968 GT 500 KR was a very special car. Many modifications were made to the stock GT Mustang. The 428 was the same Cobra Jet engine offered in the stock big block Mustang. It was the old 428 block with a lot of changes. The low riser, revised, 427 heads had huge rectangular ports. Measuring 2.34" X 1.34", the ports were larger than the 427 racing heads. A special dual-plane intake manifold held the mammoth Holley carb. Stronger connecting rods and crankshaft replaced the stock 428 pieces."

[Deuces]

Think they used the "Lemans" rods in the KR motor...

[hoop98]

KR production ended before SCJ began 1969 model year

"The CJ connecting rod differs from standard FE rods only in it's use of larger 13/32"-24 x 2 5/32" bolts (C2AZ-6214-B bolts with C0ME-6212-A nuts; the 390 and standard 428 use C1AZ-6214-A 3/8"-24 x 2 7/32" bolts with C1TE-6212-A (replaced by C9AZ-6212-B) nuts). The SCJ connecting rod is a "LeMans" style rod that is about 70 grams heavier than the CJ connecting rod. In addition to the extra material, the SCJ rod uses 7/16"-20 x 1 3/4" 12-point capscrew bolts (service part number C9ZZ-6214-A) to secure the end caps to the rod. The OEM bolts are typically replaced with stronger aftermarket fasteners from companies like ARP when assembling rods for use in high performance engine builds."

The top rod is the "lemans rod"

[Engine man]

Originally Posted by falcongeorge

PI's are kinda like the the FE equivalent of "corvette motor". Probably a 410, not that that is a terrible thing just dont pay PI $$$. Take a magnet, see if it sticks to the intake.

Not quite. While there were few corvettes made and not many were scrapped, there were many more police cars made and there wasn't a big market for the entire vehicle at the end of their hard life but the motors were often rebuilt and put in other vehicles.

[hoop98]

If it's the original engine, the codes are
M=410
Q=428
P=428 PI

C6AZ-9424-H is the 66-69 PI intake

[falcongeorge]

Originally Posted by Engine man

Not quite. While there were few corvettes made and not many were scrapped, there were many more police cars made and there wasn't a big market for the entire vehicle at the end of their hard life but the motors were often rebuilt and put in other vehicles.

Its an inside joke, I realize not everyones gonna get it.

[pdq67]

I'm here to say that all of the old FE engines are "hauling as*" motors.

From way back to the '58, 332, up to the 427's and '8's!!

Biggest deal to me was that the cast-iron intake was too heavy, therefore an aftermarket intake may lose 50 pounds or more??

pdq67

[k9racer]

Just a reminder if you are using what was called the 7 thousand rpm rods. Do NOT re use the rod bolts. These units are streach torqued. Many years ago [[1970]] I sold a 427 engine to a friend. He refreshed the engine and did not replace the bolts. He said they looked ok and he did not have the money to replace the bolts. After 15 or so hot laps it came apart. The next time I told him something he listened.. Fast forward to today I have a OT truck with a 68 427 FE its a friends old tow truck now the fastest truck that hauls scrap metal.

[James427]

Another point to consider.... if the 66 is a late production 66 the date codes may be late enough to have been installed in an early 67 Shelby. 66 and 67 engines were not stamped with a VIN so it is possible to have a "numbers matching" 428 back in a Shelby if just the date codes match. I have sold three 66-67 428's out of T-birds and Mercurys for over $3,000 each just because of this fact. So if the car is just a donor and it still has its original 428, check out the date codes and consider selling it for big bucks and buying the engine of your dreams. FE's are big, heavy, wide and their transmissions are too, so fitting them into early iron (unless it is a late 50's or early 60's Ford) can be a lot of work.

Also, for FE's and 428's in particular, people tend to call ALL 428's "police interceptors" like they call ALL SBC's Vette engines. Unless it is a "P" code, it is not a true Police interceptor engine which is quite rare. Mercury also made 410's which are basically real 428 blocks with a 390 crank. These blocks are still worth good money because you can put a 428 crank in them and you have a true 428. Let us know what you find out.

[finn]

Originally Posted by James427

Mercury also made 410's which are basically real 428 blocks with a 390 crank. These blocks are still worth good money because you can put a 428 crank in them and you have a true 428. Let us know what you find out.

Wrong.

The 410 is a 390 block (4.05" bore) with a 428 crank. Basically a 390 factory stroker engine.

Also remember that the majority of Mercurys of that era came with a garden variety 390, which looks the same as a 410 or 428.

[James427]

Originally Posted by finn

Wrong.

The 410 is a 390 block (4.05" bore) with a 428 crank. Basically a 390 factory stroker engine.

Also remember that the majority of Mercurys of that era came with a garden variety 390, which looks the same as a 410 or 428.

There is my dam dislexia kicking in again. Got it backwards, lol. Did you hear the one about the Dislexic Athiest??? He just doesn't believe in dog.