well the way i see this if your go up on the cam you will need more cr and if you go to a bigger cam you will need bigger heads if want to make big hp.and will have take it where the cam make power and at this point you will be making HP not Tq so at 2500 rpms the car will not make any hp and not much tq so you have to be carefull not to go to big on the port size of the head or the cam if the cr is low