Alright i have a 1991 Si b21a1 completely stock. Tore down the motor for rebuild and now on the final steps. Just went to do torque down the intake and do valve clearances but the darn thing didn't want to spin. I turned the motor so hard i ended up jumping 3 teeth on the intake. So i took it off lubricated the cam again (assembly lube of course) did timing again and torqued to a measly 5 pounds. Nothing. Ive searched and found nothing. I doubt the head is warped. Could it b the cam? Or the Distributor?