Morris Minor Owners Club

Please could you give me some advice on choosing a differential

I have a 1300 A+ marina engine and a Ford Sierra 5-speed gearbox.
Any advice on what would be the best ratio diff to use.
I like a bit of speed but not keep changing up and down the box.

I would be grateful for any information.
Thanks
LIZ

What diff do you have currently and what do you feel about the current performance?

4.22 standard diff ratio with 5 speed box, any lower and you will be changing gear on slopes. If you want acceleration 4.5

See how it goes in 4th which should be the same as top in the Minor box and then decide if the car can handle a 3.9 with the overdrive 5th gear. My guess is that it will be ok as it is