head fitment

Ok guys, im sure this has been covered a thousand times but i need to ask anyway, im looking at a 67 273 for my 67 Barracuda, it is a short block 4 barrel motor, my question is i have a set of J heads that i would like to put on this motor, ive heard rumors of "notching" the block? Is this correct for one,and what other mods do i need to do? The cam selected is a 509/292 solid, if that makes any difference............

thanks for the help

Doug