RE: Evo 70 vs. 74
No shape difference at all between 05 and 06 on the 74 (the 80->83 had lots of change). 06 Fin is a wonder though. Straps are nicer too. With a 5.6 I tend to sail the Drake Natural (cnc) 23 or 24. You can even use the 25 too for B&J, but at your weight the 24 will do the trick.