Norb,
I agree with most of what was posted about Iron vs Aluminum heads and the iron heads will work. I saw one set on a motor that John Gallina had that were running in the 7's so it's possible to make good H.P. with them. I think there is a reason Buick stop casting them back in the early eighties and that is because Aluminum is preferable as a material. Aluminum does have a different expansion rate but is lighter, more easily repaired, and less prone to detonation due to the fact that Aluminum dissipates heat more readily. Don touched on a good point which we visited in another thread that with an Iron head on a street turbo motor 9.5 to 1 compression is a bit high. With an aluminum head it will work fine.
Neal