I am putting a 72 A body rear into my 71 (originally a 7 1/4" w/9" drums). Kragen lists a different rear hose for a 71 and a 72. Rightstuffdetailing.com lists a hose for 70-71, and 72-76 (70-71 judging by the picture is the same, minus the tee on one end). Rightstuff also lists different hard lines for a 70-72 vs 73.

Anyone know for sure which parts I need to do the job?