Ok i was doing some research and could not find any information about these types of blocks made by svt n Romero factory plant.. My original block was a wap hand made by rpms n his partna (Dont remember his signature plate name only RPMS) Ford had to repiece my block by using both wap n Romero in the mix.. Outside core seems to be all Romero which is the top n sides of the engine n the wap pieces seems to be the center , front n back of the engine i think.. This had to be done due to me tearing up my block n was no longer usable.. Ford assured me that its still all aluminum inside n out..