I am not looking at building a car with a vintage engine, but when I read the discription of the XO class I have some questions.
First 1959 or earlier design. Ford introduced the 332 FE in 1958 so it, and all other FE's are legal to run in the XO class as long as it is under 325cid, XXF or XXO 325-375cid
What about the SBC? 1955?
When do heads become "speciality" heads?
What am I missing? Original engine dimensions? Cast heads only?
Just trying to wrap my head around this.
Thanks