also to make the ICM last longer do this simple mod... unbolt it from the block and add 2-3 washers behind this. Because the heads get so warm they transfer the heat to the ICM with in its origional form is flush with the block. Pull it off and give it some room too cool...
only took me about 5 min to do...
also here is a very good website with a ton of info:
http://shbox.com/1/4th_gen_tech1.html