the rack needs changing becasue the linkage brackets bolt to it, the 1.3 doesn't have all bracketry required for the 5 speed big block linkage. you may be lucky and rack been replaced in the past however.
as i say you can use the old mount bracket, drill off the spot welds to remove it from the leg. flip it upside down and reweld it. You may need some patches of metal to repair and fill in some gaps, but if you can weld a mount then this wont be a problem for you.
this is where you need to put the driver side mount:



and this is what your rack needs to look like:

