To me, unless there is no budget limit, the 422" 340 or 360 stock-block-based engine is the best CID bang for the buck. That's a 4" crank with 4.100" bore. It needs W2/W5 or Trick Flows with 2.05-2.08" intake valves and roller valvetrain to really be worth it, IMO. The extra cubic inches are nice, but the 4" combos have torque aplenty and still rev quite nicely. You need some serious heads to utilize 476", and lots MORE MONEY than even an R-block!
