I don't know why but they've had this problem for a minute. Links seem to disappear after half an hour or something. Well, the rulebook is still there. http://www.usacracing.com/assets/files/qm/rulebook/Appendix_1_Technical_Specifications.pdf
copy and paste that into your addy bar or simply click on it and it will take you right to the tech specs portion. If you need the others just let me know.