What might my 360 CR be?

fill the valve reliefs with clay till they are "dead even" flat then take em out & drop em in to your CC ing burette that has some fluid in it & see how far the fluid rises on the scale. You know the bore and stroke and deck height and your choice of head gasket thickness. all that is left is a guestimate of the head CC's you will be using. Many online calculators good for SCR. Reportedly for sure the Wallace racing one (& I'm sure others/but not all) are accurate for DCR (cam figured in). EDIT Knead the clay into a rope before you drop it in the burette so it sinks all the way