Iron Heads
You might consider installing the engine with the iron heads so you have the aluminums sitting as spares on a shelf till you are ready to have them ported.
They have a 62-64cc chamber so they are lower compression.
They are less fragile when overheated and FAR FAR less prone to head gasket problems than the aluminums. Not that the aluminums have frequent head gasket toubles but they are more prone to it than the iron.
They were delivered tuned for 87 octane fuel.







