The bellhousing is stamped to indicate what motor it bolts too, in your case an R series, not the gearbox. W55,57 and 58 g/box's are interchangeable, however some have the clutch throw out fork on the opposite side, depending upon model. In the Corona Avante 22RE the g/box was the W58, IIRC. The original transmission type might be stamped on your build plate on the firewall....check it out.
Mitch.