You are going to have trouble finding a big frame that does have toe overlap. I have a couple of track bikes and only one has toe overlap (w/ size 50 Sidis), and the is an vintage Italian Viner track that was super steep and extremely short wheelbase. I am also 6'6' so I know how you feel. The old 61cm GT track frames have a big top tube (61cm), 64cm Fuji track that is made anymore as well, plus the Mercier, Surly Steamroller, Giant Bowerys, etc.