Compression...

Doubling head gaskets? wow. That's one I've only heard of in desperation or lack of understanding conversations. Indy uses thier own Wiseco pistons IIRC, and I dont know the size of the dish. But, the Magnum heads are about 7ccs smaller than the typical LA heads. SO your compression will be up in the high tens with 63cc LAs and over 11 with 58cc Magnums. You can run an MLS (Cometic) type gasket, but the heads and block's deck will need ot be milled to the proper finish. You can also enlarge the Magnum chambers if yo uhad to. Depending on the cam choice, 11:1 may be fine for high test unleaded. Depends on how good the package is put together. I've seen Indy's work. If you are buying it thru them and they built it, it's priced about 20% higher than it should be assuming they do everything right. And that's a big assumption with them.