Yes, I had a look at drafts, but the movie ends up slightly different to the scripts. From what I thought I heard ("Pula Blanca"), I tried Quechua language translators on the net. I must have the first word wrong. Nothing seems to come up. And 'Blanca' is most likely 'Blanco'. Ultimately I guess Barranca is saying to the Indian porters, "Follow the white man" ("Follow Whitey").
Just from the point of view that it is the first line spoken in the Indiana Jones series, I was keen to know exactly what he was saying.