FoT, Pages 428 and 429 of "The Complete Official Triumph TR6 & TR250 1967-1976" manual published by RB Bentley Publishers will give you all the dimensions you need to verify and true your frame. Take the book to Kinko's and have them enlarge the pages 200% for easy reading. Allen Allen & Jody Washatko 1971 TR6 - Number 6