The intake valve does not close until after BDC. even on a stock cam.
The bigger the cam duration the latter the intake valve closes past BDC.
set the timing using a timing light. 34 to 36deg BTDC @ max mechanical advance.
The best initial timing will depend on the cam used in the motor.
generally 12 deg +/- for a stock OEM camshaft. You cannot set it by ear.
Did you line up the cam gear timing dot when installing the cam?