Bassmanbob,,

I have ridden with a couple that the captain was about your height and the stoker was probably 5' 2"ish. They rode an older small Santana and it fit them well. The captain's seat tube length of an older small Santana is 50.5 mm with a stand over height of 72 mm (see Gear-To-Go Tandem Bicycles for specs on older Santanas). If your pants inseam is 29"if should be able to stand over this bike. Notice the lowered top tube of this picture.

Tailwinds,
Charlie