Big blocks fall into 4 version for 454's.
Mark IV = 1965-1990 ( Classic BBC)
Gen V = 1991-1995 (this is the one that takes alot for $ to get the good Mark IV topend on)
Gen VI = 1996-2000 (This is the "real" successor to the Mark IV, parts interchange better. No mechanical fuel pump and no adjustable valves)
Gen VII = 2001-2009 (The 8.1L 496 BBC, it has different oil pan rails, 18-bolt head bolt pattern, symmetrical intake ports like the LS series along with the same firing order and ECM...
A 1997 is a good motor. If you find someone to tune it I would leave it EFI personally. You can even retro it to use the LS computers, so anyone that can tune a LS can tune it. You should have no problems running it in front of a TH400.