About Those Magnum Head Cracks:

The majority of factory heads will show cracks. Of that, about 40% of those actually have any problem associated with the cracks. On some they dont crack, some crack and never reach the cooling jackets, and some reach the jackets and make a problem. The best bet now is to get a set of EQ Magnums. Assembled and ready to run they cost less than re-doing a set of factory ones, assuming you get a set of good ones.