I have an aluminum head on my '23 touring and I'd like to find out who the manufacturer was. It has the usual FORD script and made in USA. There is the number 4 cast into both in the front and in the rear of the head. I have never removed it but I suppose it is a high compression head--otherwise why replace the original iron head. I seem to be getting quite a bit of knock with the spark advanced and would like to see if there is a remedy. Any help you can give would be appreciated.
Is there a Z on the water outlet?
Might be a "Reeder" alum high compression head. Mark can be found inside the water outlet.
Older post on these heads, the early ones were cast with Ford script.
I don't know which head it is but the knock may be corrected or at least lessened by running a little less spark advance and/or higher octane fuel. Both are easy fixes to try.
I noticed that I don't need as much advance with my new Prus high compression head.
The Reeder heads (Performance T Parts) have a 4 on the water outlet.