bungi

hello im john or bungi to my friends i have a 1970 mk2 cortina 1600e with twin 40s and fast road cam pics are in garage not sure were to post this question the tina is my everyday car and i travel 80miles a day to and from work mostly on motorways but its a bit sreamy for my liking my last classic was a hb viva with 2300 engine with a 4speed overdrive gearbox my question is is there a 5speed i can put in the tina without too much chopping and cangeing thanks in advance