Performance
Correct me if i'm wrong but I don't believe there is a compression limit nor a displacement limit either in the Pure Stock and also the F.A.S.T class series of racing and so yes any of them that want to compete at the top will push all they can.
In Pure Stock, like what is run at the PSMCDR event every year, the rules are pretty restrictive.
The compression rule was revised several years ago to allow:
Factory advertised CR, +1.5 points.
Rules
No strokers, no big cams, no porting on anything.
Can’t even run a line lock.
The F/S class in FAST is supposed to be the same.
The actual “F.A.S.T.” Class has very open rules, with the emphasis on the car “looking” stock........ the “A” is for “appearing”.
So, strokers, ported everything, high CR, roller cams, etc are the norm there.