they are simular from 71-74. but as you know spline count will be different. also your clutch is smaller. answer for number 2 .they are different.the v6 did not get a four speed manual in the pinto, only the mustand Ii, ford capri and 79 fox body mustang got 4 speed manuals.answer for number 4 is yes. there is a 5 speed that will bolt to a 1600. but you have to go to england to buy the proper bellhousing for it. the trans is the type 9 5speed. so unless you have the money for a trip.your out of luck. also if you wanted to know about an automatic. only trans is the borg-warner type 35. found on imported cortina mk1 and mk2. hope that helps