[RodKnock]

If you ask Barry R from Survival, the Blue Thunder heads make the most HP right now. The only problem with the BT heads i sthat they have raised exhaust ports, which may lead to header and exhaust issues, especially for those Cobras with their sidepipe holes cut already.

The largest FE I've read about is a 527ci based upon the Shelby FE block. I believe these blocks have more material than the Pond or Genesis blocks which are reproductions of the original side oiler, where the Shelby FE block is not.