Early Mustang Engine Numbers

By Classic Car Restoration Club Editors

Q.

I have a classic car question that pertains to the engine size and year manufactured. I have a 1965 Ford Mustang and I can not find the location of the engine block serial number. Where is the serial number located and can you tell the block is a 260 64 1/2 by the serial number?

A.

The differences between 1964 ½ Mustangs and 1965 Mustangs is exactly the stuff perpetual arguments are made of. To the best of my knowledge, Ford did not use engine serial numbers in the mid sixties. The 5th digit in the cars VIN designates the engine size, and a “F” in this place would indicate the engine should be a 2-barrell 260-cubic inch V8. The year of the engine is designated by casting number; with the first letter “C” designating the sixties followed by a number. Which is right for a 1964 ½ “C4 or C5”, that is where one of many arguments begins. The date codes of the castings may give you a better idea, as the components need to be manufactured before the cars production.

From 1962 to 1964 1/2, Ford used the 260 V8 engine. This engine was the predecessor to the 289. The 289 was developed in 1963. The main difference between a 260 and a 289 is the 260 has a 6 inch space between the motor mount bolt holes, while the 289 has a 7 inch space.

All 260 engines have a 5-bolt bell housing bolt pattern. The 1963 and 1964 1/2 289 engines have the same 5-bolt pattern. The 260 has a smaller cylinder bore. Ford did not make a 260 4V engine. You can always add an early 289 4V intake to your 260 engine if you want to make a “D code” style engine (“D code” is a 1964 1/2 289 4V engine)

Wrench Safe,
Mark

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12 Responses to “Early Mustang Engine Numbers”

  1. Scott

    I have a 65 Fastback that doesn’t have a driver’s side door data plate. Is it possible to obtain a new one? I purchased the car a couple of years ago. It would be nice to have the build information. Thanks for any advice

  2. THOMAS SILL

    289 2V... JUST ABOVE STARTER... 5A20...5=1965 A=JANUARY 20=20TH DAY...... THEN C5AE C=289 2V 5-MADE IN 1965 A=PRODUCED FOR FORD GALAXIE E 6015 289 BLOCK... CURRENTLY INSTALLING ENGINE INTO A 1961 JEEP WAGON. WITH TRANS ADAPTER TO ORIGINAL TRANSMISSION AND 4 WHEEL DRIVE. THEN A 1949 JEEP SEDAN DELIVERY BODY WILL COMPLETE THE BUILD. ANY INFO ON ENGINE WOULD BE APPRECIATED.

  3. Sal

    I have a 289 Ford Mustang engine, the stamp number on block is 8R105067. The stamp is located on the rear of the motor on a flat plate. I was told this was a hi-po motor can anyone confirm if it is a hi-po by the numbers I have included. Thanks

  4. Allen

    Im trying to find out what motor I have in the car there is only one number i can find and it is behind the intake manifold and above the bell housing if "F then 2 symbols that look like upside down nails and then 3997" do you know what this could be? The car is a 1979 mustang cobra foxbody

  5. wendell Talbert

    on my previous comment i neglected to say that i have the vin and the engine sn. i tried to get help through ford to no avail. is there a listing somewhere to match vin numbers to the original engine numbers for my 1970 mach 1

  6. wendell Talbert

    i am trying to see if the engine in my 1970 428 cj mach 1 is the original.

  7. Matthew Rose

    I have a ford head question. I have a set of heads on my 302. they are big valve big intake and exhaust ports . they have 1/2 head bolt holes. But they have no ford casting numbers at all. The one head has numbers cl 1991 and s/n sb 990-2 1181. The other head has numbers cl 2018 and s/n sb 990-2 1177 these are the only numbers on these heads. They also have screw in rocker studs . I'm trying to figure out what head I have can you help me ? Thanks

  8. Ken Richter

    Were there 6 Bell housing bolt holes after 1964 1/2 in the 289 and 302 engines.

  9. Tony Kovar

    Your earlier comments below from Charles Georgoudis are mostly correct with the exception of a few noteworthy things. First, HiPo "K" Code motors and their transmissions as well were all stamped with the VIN numbers of the cars that they were installed in from the Ford Factory. The only "K' code motors without VIN number stampings were original " K" Code Ford replacement Crate motors. Second, Starting in 1968, Most (but not all) Ford Plants started Stamping the VIN numbers of the cars on the engine blocks of the cars that they were installed in...but the practice was only done to about 50-60 percent of the cars during those years and after and the practice was not consistently spread throughout all of the Ford factories unfortunately. Tony K., MCA#70001

  10. Charles Georgoudis

    The casting number is only that. A date that the engine block was cast and nothing more.It may give you an idea of the model year, but not necessarily. October was usually the date where new model years were introduced. A block that was cast in 1964 (C4) may have been installed into a 1965 model that was built in October through December of the previous year. The assembly date code is stamped into the block on a small extension at the left front side of the cylinder head deck surface, (left, while sitting in the car). This code can be erased if the head surface has been decked. Engines were usually assembled about three months in advance to installation, (when all goes well at the plant). The assembly date code gives the year, month and day of assembly followed by a letter for the assembly plant. This is not always stamped after the date code for some reason. An engine that has a code of 4L30C deciphers as: 4=1964, L=November, (L=consecutive number of the alphabet with the letter "I" omitted which results in the eleventh letter for the eleventh month), 30=day of the month, November 30, 1964. The letter "C" at the end, indicates the Cleveland assembly plant. This code was for a 289 that I have in my possession. An indication of the engine type and displacement is obviously not in this code. Ford didn't stamp VINs on their small block engines in the 1960s, the only exception is on the "R" code 289, (289 HiPo), where the vehicle serial number is stamped into a pad located in the rear of the block. If there is a "W" at the end of the assembly date code versus a "C", this would indicate the Windsor assembly plant where all 302 engines were built and some 289s. There has been instances where blocks that had a casting number designated for 302 engines were used for 289s in the final year for the 289 in 1968. A shortage of available 289 block castings facilitated the use of the 302 blocks. An example of this block is the casting number C80E-A, where both displacements can be found.