That is the same shifter used on early Mustangs and it bolts directly to the tailshaft, the reason the arms are so long. My guess is your transmission doesn't have the bosses to mount the shifter or they aren't drilled. It's too late tonight, but I have a spare 3 speed that came out of a '66 Mustang and tomorrow I'll post some pictures. By the way, IMHO, the shifters are junk, they are difficult and expensive to rebuild and they don't have a reverse lock-out. I put a Hearst in mine years ago which requires, in a Mustang, cutting the floor left of center and mounting it at the point where the tranny mounts to the bellhousing.