Im rebuilding a holley 650dp I think its a 4777 ,one of the accelerator pumps had this spacer in it. I am guessing it is to make it a 50cc pump. when I pulled it apart it only had a 30cc pump inside with this spacer. Anybody ever seen this before, I am not sure if I should just use this or get rid of it and put a 30cc pump in it. It says on it superspacer if that helps.