I have to say I know why they called him Da Grump ! I was at the York show around 2004 or 5 somewhere in that era when both Sox and Jenkins were both there. Well I saw Ronnie Sox who was there with his wife and asked to get the artist pic they had of his 68 Cuda racing the Jenkins 69 Camaro. It had both cars pulling the wheels. On the bottom of it was the words "Ronnie Sox 5 time world champ ". Well Ronnie signed it and I talked with him for a good bit as he was the nicest person to talk to. I was so happy that my childhood racing hero was such a nice guy. Well I went to the other side where Jenkins was and asked him to sign it also since his car was in it. So he signed it without saying a word to me and then I stuck my hand out and said ........thank you Mr Jenkins. He just looked away and would not shake my hand. So I walked away saying to myself.....what an a-hole ! Ron