I would treat that thing as a core. IF it was truly used for racing (how many people actually raced a slant 6/904 pb?), its likely gonna need rebuilt, new clutches etc. That said, the pushbuttons are a completely different animal, especially the 1963/1964 versions, than a regular 727. So you're gonna have to make sure its rebuilt right. OH and make damn sure you get the right trans filter, the one with two holes, one for each pump. MOST auto part stores only stock the later, 1967 and up 727 single hole filters.