A little more info would be helpful. Depending on the gas you can get on the water and whether it's intercooled, you could go as high as 9.5 to 1. If all you have is 87 octane and no intercooler, stick to 8.5 to 1. Less compression and more boost will make more hp. If you have any idea that you might want to change pulleys in the future, stay with the lower compression. If you have the 3/8 bolt rods, don't machine them for larger bolts. That will just weaken the rod cap. Replace them with the best 3/8 bolts you can get. ARP Wavelock or equivelent. Valves in a supercharged engine should alway be top quality. Manley or Ferria stainless intakes and inconel exhaust. Get a good valve job from a person who knows what they're doing like Jim Valako aka Jim V here on the board. Use 2.25 intakes and 1.88 exhausts.