All the guys I know who run heads up, N/A or power adders, that have raced with cast grey iron and or with Compact Graphite Iron blocks and with good race aluminum blocks with the same parts in them ran faster at the track and made more power (30 to 80Hp depending on the race,r motor size and RPM and who was telling the story) on the engine dynos they tested on
What type of blocks do all the Pro Stock team use
I'll give you a clue, they ain't aluminum the last time I checked