Compression ratio + hp?
Sounds like a good combo. I would think easily into the mid 300hp. Was there any porting done on the 596 heads? There’s a lot of meat left in the bowls on that casting, would really help to clean them up. Also did you plug the smog holes. The easiest way is a crack repair kit. There’s a proses of drilling and tapping a hole on either side of a crack in a block and then screwing in a cast plug. The plug will snap off when it gets tight. These plugs work great, just tap the smog hole and screw in the plug