Saw pictures of Keith on-set of Over the Top but he got replaced as main opponent.
He is still credited as "Arm Wrestler" on IMDB.
http://www.imdb.com/name/nm0428531/
Doesn't sound like he did much to win favor with Stallone, from Keiths own mouth
"Short story about me and Bruce and the film. They actually shot the final scene (competition) during the actual IAC World Championships. As the picture below shows. We me and Bruce had to go up againzt each other. So now all the cameras came over to our table to film us. As we lock up I feel someting on my shoulders and its Stallone hanging on my right shoulder lokking over to see our match. The cameras were on Bruce and my camera right. Well I got a little pissed and let go of the grip and turned around and looked at Sly and said excuse me. He said sorry and back away. We lock up again and they say go and about 2 seconds into the match I feel Sly touched my shoulder durng an actual match. I eneded up beating Bruce on about 20 second or so can't remember. But, I turned around and looked down at Sly and said f**k you and pushed him down. He fell on his ass and about 10 guys come running up on stage to pick him up. I leave the stage to sit with my friends and they all high fived me. Nothing happened and he left the stage.
The production made the competition last 19 hours. They wouldn't people leave the audience who worked as extras. They actually locked the doors. they fed everyone and most people got pics. I remember sitting with two girls and they were talking to me and taking pics and one of them asked me where Sly was. He came walking in with 10 or so bodyguards and I pointed at him and said there he is. They both look at him and at the same time said "Man is he skinny". He weighed about 175 for the movie. They put sandbags on the scale to increase his weight to 190 or so."
