that should be an oval port head with a d-shaped combustion chamber. although if you used a later d-port n/a head with the heart shaped combustion chamber it would slightly up  the compression and give you a little more bottom end torque. the later heads were drilled for both bolt patterns on the intake side of the headand the early ones werent. the difference in the pattern is on intake port 1, the top left intake mount point on the head will have 2 drilled and tapped holes on the later head. your origonal head should only have one drilled and tapped hole there.