First Gen 600 and 700 motors did not have VES. No big block 600 had VES. In '02 the 700 big block got ves.
You can put reverse on any of the VES motors with a few changes like wiring harness/cdi/flywheel depending on year.
You can also put reverse on the '00/'01 700 big block but you'll have to use the VES CDI map unless you know someone who can remap the CDI for you.
sled_guy