by David Hunn originally published as 289 Heads Up in the August 1977 RootesReview

One sure-fire way to more oomph out your stock 289 CID engine is to do some mutating and transplanting of parts from other FoMoCo engines. Specifically, let’s talk about heads. If you are running an early (’63-1/2 – ‘64-1/2 ) engine, your intake valve is 1.67 inches. If your 289 is a later model, (‘64-1/2 – ‘68-1/2) the diameter is slightly larger 1.78 inches. It’s logical if you can increase the size of the valves and the combustion chamber, more fuel/air mixture can get into the combustion chamber. If more can get in, more will be burned better performance will inherently follow. Of course, there is an optimum size that can be surpassed.

First of all, you must accumulate same of that indispensable stuff known as money and must locate some specific parts. Perhaps at your local swap meet or in the paper you can find some good 351 Windsor heads for sale. We are going to interchange these Windsor heads with the stock 289 heads that are currently on your engine. Not only will the combustion chamber size be increased, but the valve size will increase substantially.

Done properly, you will be able to “bolt on” 30+ more horsepower. The big Windsor heads that have valves that are 1.84 inches in diameter –just right for the 289 to breath easily! Along with the complete 351-W head assemblies you will need new head gaskets, cylinder head bolts, and new intake manifold gaskets. Because the 351-W combustion chamber is larger than the 289, compression must be restored by using pop-up pistons.

351-W intake manifold gaskets, part #C90Z-9433-A, must be used in order to keep from having a leak in the water passage at the end of each head when your existing 289 manifold is re-installed. The new head bolts are needed because the 351-W uses ½” bolts while the 289 uses smaller 7/16” bolts.. Parts #C8OZ-6065-A (10 required) and #C8OZ-6065-B (10 required) will fix you up. They are special bolts that are a washer integral to the head of the bolt. This integral washer gives the 7/16″ bolts plenty of bearing on the head for proper support. The pop-up pistons are no longer available at your Ford dealer. The right-hand pistons were #C90Z-6l08-AA and the left hand pistons were #C90Z-6109-B. These babies-will raise the compression to about 10.5:1–if you can find them. Otherwise you must use after market pistons. Use 289 or Boss 302 head gaskets C8OZ-6051-B or DlZZ-6051-B.

This head is an excellent way to increase performance. I once more stress that these are 351 Windsor heads. If you pick up 351-C or Boss 302 heads you will run into a lot of problems. The Cleveland heads will physically bolt on, but the water passages won’t match up. This swap is not practical because you would have to extensively redesign the water outlets for a proper fit. Stick with the Windsor heads and you will be satisfied.

Corresponding cam, carb, and ignition changes that can be made are by your imagination or your pocketbook. With 351-W heads the 289 “little screamer” has great breathing ability. You are faced with the tempting option of taking advantage of installing a larger carb, wilder cam, freer exhaust, and a hotter ignition system. With proper balance of cam and carb your Tiger will transformed into an unbelievably powerful machine. Any hopped-up Tiger is special — they require drivers! Be careful and have fun!

Technical Editor’s Notes:

Part numbers given in this article are from the Ford Muscle Parts Books circa 1969.

The following are part numbers given in the 1972 Ford Off Highway Only Parts book:

351-W cylinder head…………….. DlOZ-6049-B
L. H. pop-up piston . . . . . . . . . . C90Z-61 08-C*
R.H. pop-up piston……………… C90Z-6108-AB
289 cylinder head gasket………… C80Z-6051-B
Boss 302 cylinder head gasket……. DlZZ-6051-B
Intake gaskets – 351-W ……………….D1AZ-9433-C

*Addendum to Ford Off Highway Parts books changed number to: C90Z-6109-C.

351-W heads can be readily identified by the 11L11 shaped water passage and extra bolt hole at each end of the head, as shown below.

head sketch

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