Magnum 5.9 lifter removal

I've got a 72 duster with a magnum 360. I'm getting ready to do a cam and lifter swap in the car, upon doing some research, I read a couple threads that said you had to remove the heads to get the lifters out because they were too long to slide out of the valley. The car currently has a Comp Cam 264HR-12 and Comp Cam lifters. I was planning on swapping over to Hughes. However if I have to remove the heads, then that may change my game plan a little bit.