Don't understand cams

Thanks again RRR for the links.........but as alway, reading and learning, cause desire for even more understanding.
Ok here is my question. It has to do with overlap. I had this all figured out long ago but, NO.

My 340 had a MPP cam .474/280* cam with a 60* of overlap. My new cam to match my new 408 motor has a Hyd Roller Cam that is much larger.562/.550 lift 243/247 duration @.050". Gross(@.006") duration of 294/297)
So this cam by Comp, does not have a Overlap spec but by using the cam card i see that the intake close and exhaust open spec's it can be figured out. or so i though...........
so Intake opens at 19* btdc and exh close at 13 atdc. so my math says that i only have 32* of overlap. Now these ## are a @.050"
I realise that i'm comparing apples to oranges here but, that is only half of the overlap, of my smaller cam.
Now i'm sure that they differ because of the gross and @.050" But over 30+ degrees.....less???