These cams:

284/108 cam------open---------close

intake--------34*BTDC-------70*ABDC

exhaust-------70*BBDC-------34*ATDC

278/290/114 cam----------------------

intake--------25*BTDC-------73*ABDC

exhaust-------79*BBDC-------31*ATDC

Of course, one could get a better idea of the true affective overlap if we knew the cam timing events at .050 lift rather than at 0 lift (I am assuming that is at 0 lift)