B-. I liked that the story was updated to the 1970's, but the deliberately campy approach doesn't really work for me.
You've seen Guy Standeven in something because the man was in everything.

It's a great movie, an excellent updating of Kong, which is very unfairly trashed in some circles. Had it been merely released a year later, it would be universally regarded as a classic, instead of a movie over which people fight.
"The Dig"
http://cinemarchaeologist.blogspot.com/

Didn't like it the first time I watched it, but it grows on you.

C of the Kong movies I've seen it is my least favorite.
Worth watching for Lange's legs, though.