rocker problems

I just bought a set of aluminum large port commando heads from MP (mopar performance) for my 340 which require a set of offset W2 rockers (which convienently, MP doesnt make anymore) but they are still classified as LA heads. I finally found a set of aluminum full roller rockers from Harland Sharp and ordered them. When they came in I tried the heads and rockers on a 318 Im building for a guy and found nothing lined up. The pushrods were hitting the bottom of the heads not allowing them to seat at the new aluminum rocker set screws. I called Harland Sharp and wxplianed to them what haapened but they assured me the rockers are corrrect. Is it possable I have to modify these $2400.00 heads or are the $1800.00 rockers wrong? Any help would be greatly appreciated. :help: