Is there any type of indicator light on the dash for when the V-8 switches to the V-4 mode ? It appears some GM vehicles do and others don't.

There is not that i have seen so far and nowhere to change that in the DIC either that i have found.

I cant even say if it has ever kicked in for me because if it has, i didnt notice it.

There is no light , and there probably isn't a point to it other than to say "oooh , I'm saving gas!"

It wouldn't be hard to wire one up, just hook a light to the AFM solenoid.