Brodix B1-BS Aluminium Heads ?

I ordered a set of Brodix B1-BS aluminium heads on monday. 2 to 3 weeks untill delivery. I had a head gasket blow after 3rd round on sunday, on my 440, with cast iron 915 heads. The gasket blew out the back of the head towards the firewall. I figured I would up grade to the Brodix heads, while it is apart. Anybody know the weight saving, by switching to these heads?? Any guesses on horse power increase, or et gains?? If not, I will find out in 3 weeks I will weigh the car on the same scales, that I weighed the car on 4 weeks ago, and also run it down the track and see how it runs!The Brodix heads have a 65cc chamber, I don't remember what the 915 head cc is?