Masters of Motors (MOM) the new EngineMasters Challenge (EMC)
I have no porting experience with 308’s.
The motors I used them on we’re 2bbl oval track builds where no porting was allowed, and they had to use the 1.88 valve.
That’s why I figured a junk head for some R&D might be worthwhile.
There might just not be enough meat on the floor/short turn to allow them to achieve the big number without putting a hole in it.
And...... you’re only allowed one hole, period.
Sans any R&D....... I’d use the X heads.