Blake, My engine was built by RV Engines (Richard Vania) in Alexander N.Y. By the time I was done it cost me around $5000. But that included a steel flywheel, FMS clutch & pressure plate, FMS "Performer" intake, Brodix alun heads, and a Canton road race
oil pan. All I supplied was the Edelbrock water pump, MSD distributor, the B303 cam & FMS roller rockers. The cost for the Scat steel crank and pistons was, I believe, the same for the 331 or 347. If it is a street engine go for the 331. For the ultimate performance the 347 is the way to go but, I don't think it will live as long on the street. Try to decide how you are going to use the car and then build your car/motor accordingly. HAVE FUN!....MH