Big twin crank threads Home › Forum › Ask A Member › Big twin crank threads This topic has 0 replies, 1 voice, and was last updated 2 years, 10 months ago by trex014. Viewing 1 post (of 1 total) trex014US Member - 2 YearsReplies: 56Topics: 42 May 15, 2021 at 9:12 pm #238431 Does anyone know the thread size of a 1955 big twin 25hp crankshaft? Thanks Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In