Couple of things. I think aluminum heads on a N/A 231 is a total waste of money. You need the larger bore of a 4.1 to unshroud the valaves so it can breathe. In a car the has anything over 3000 pounds the 3.8L is also a waste of time and money. Need more inches to get the torque to get that pig rolling. Finally, in an N/A application the compression needs to be just over what you think the max should be or else it isn't enough. Don't even consider anything less than 11 to 1 with the gas you have available. The bigger the cam, the more compression you can get away with and the more compression you will need. What cam are you thinking of using? I would think a 224 ish would be a decent starting point but it all has to match.
AJ, what did Erik ever do with his Regal? I never saw it complete.