you heard wrong, just search around here
http://www.k20a.org/forum/showthread.php?t=102149
http://www.k20a.org/forum/showthread.php?t=80101&page=3
you heard wrong, just search around hereFrom what I gather, the newer "K24Z" blocks arent compatible with the older K series heads.
Yes, you can use the k20z1 rocker assembly on the k20a2.