Is this the correct book for small blocks?

the FSM is a must have, IMO. the Mopar Performance "A engines" book is a great resource. if had to pick one to compliment those two, it would be the larry shepard "how to hot rod small block mopars". also, that book has a "recipe list" in the back for engine combinations for specific power levels.

having many points of reference is always a good thing, the more literature the better.

300+ HP on pump gas with mild manners should be a breeze. 9.5:1 compression, a cam under .500 with reasonable duration, airgap and something in the 750cfm range, headers or 340 manifolds.

unless you enjoy the work, or want to do it for the experience, having the machine shop assemble the bottom end won't set you back much more money and you can breeze thru the rest of assembly.