Camshaft to Small???

A quick look in the Keith Black catalog has only one piston for the stock stroke 400. It is a KB240 flat top, 5cc 2V notch, 1.908 ch. The Stealth heads are listed at 80cc but often come 82-83cc. His heads have been milled .010". With approximately 1 cc drop for for every .0065" milled, you can all start guessing the compression ratio the OP may have. Figure a safe dynamic compression and figure a cam that will meet his needs. Good luck all.