Are my 289 heads hi-po

[turp23]

They were advertised as so when i bought the car. The number I got off one of them was 289 66 5F9. Any info?

 

[4G-KDMP]

didn't the 66 289 hi-po have solid lifters?

 

[wythors]

According the FRPP catalog, the Hi-Po heads had threaded rocker stud mounts and a recessed spring seat.

didn't the 66 289 hi-po have solid lifters?

Yes it did, but the heads themselves have nothing to do with that.

 

[Modular2v]

According the FRPP catalog, the Hi-Po heads had threaded rocker stud mounts and a recessed spring seat.



Yes it did, but the heads themselves have nothing to do with that.

but the valve springs on the heads would indicate whether or not it had solid lifters

 

[turp23]

So what else do I need to know to figure this out?

 

[Hi-Po]

Early Hi-Po heads have casting numbers C30E or C40E-B. They had 1.67 intake valves and 1.45 exhaust valves.
In mid 1964 casting numbers C50E-A and C5AE-E were introduced. They had 1.78 and 1.45 intake/exhaust valves.
In addition a C7ZE casting number was introduced in 1967.
Later service replacement heads were C8ZE-B.

Hi-Po heads had a little higher compression ratings and also smaller additional "damper springs installed inside the larger springs - but these may be lacking on incorrectly restored heads.

Apart from the casting numbers Hi-Po heads also has cast in spring seats and screw-in rocker arm studs.

Hope this helps you - info is taken from the "The 289 High Performance Mustang" book by Tony Gregory.

 

[88mouse]

if the heads are off. You can look at the combustion chambers and if they make a heart shap they are hi-po's