I personally don't have any expierience with blowers. If I were in the market for a stock block rebuild and limited to a 302/306 with a carb I would go the 9-10.5:1cr route with the nitrous. Focus on buying the best heads/cam you can afford. That is were you will make your power. You truly need to know exactly what you want to accomplish. Durability/modest power or power/less durability. What I would do is refurbish my rods & crank. Machine the block,etc, new pistons/rings,gaskets,bearings,etc. TFS 190-205cc heads,custom hyd roller,Eddy Vic jr intake,good 650cfm or so carb and a small nitrous kit for the strip. With a descent suspension,tire,chassis,and 3.73-4.10 gears you should have a car capable of solid drivability with enough to run 12's n/a and 11s with nitrous.