I have a set of cast L98 heads laying at my house. I know that you can mill down the Alu. ones to get good compression but can you do the same with the iron? Has anyone done this? A buddy had a set of the swirl port heads, dosen't want to spend much money so that is why I ask. Thanks guys!

 

you don't need to mill down the aluminum ones. They have the same compression as a 305 TBI. The iron ones have bigger chambers.