Cerwin, if the 360 is out of a pickup, you'll probably have to repalce the oil pan to het it to fit in the Valiant. You car requires a center sump oil pan and I don't believe the trucks don't have those. The 727 will fit with minor modifications. Most people report they had to hammer the firewall/floor seam flat to get clearance for the 727. On my 66 Valiant the 727 just slid in place of the old 904 with no mods necessary. For what it'll cost you to get the required parts to keep the 3 speed, you might be better off running the 727. Just put in an aftermarket floor shifter like a B&M or Hurst and be done with it.