Mk1 Gearbox questions

[Maxx]

Got the subject right this time - sorry
Anyways

1. Can you change a 1.2 gearbox with one from a 1.4? If so does it make a difference or are the boxes the same??

2. Whats the most power you can but through a standard 1.2/1.4/1.8 and 2.0 gearbox before it breaks??

 

[MAXIBOY]

2.0 litre box good for about 250bhp in good condition