thats if your tach and spedo are right both need to be verified
4.30s is the closet gear ratio a 228@50 cam with 4.30 should burn the tires@ will 2 gears stock verter or not
until you verify the easy chit youcant get to the harder chit like the cam
more then likey you have 3.55s not 4.30s
the cam could be advanced 10 degrees just as easy
how many inches of vacuum does it pull at idle?