Dizzy DIff Conundrum

[Edward.21]

good evening all
I'm in the process of restoring my van and i'm just thinking about the diff, i'm not to sure what all the numbers mean am i right in thinking that the vans had a lower diff ratio for pootaling around town? i'm going to be doing the odd motorway trip and id like to put a higher ratio diff in. what is a good ratio to look for for motorway cruising. i also have a tuned 1275 to go in her will the diff hold up to this?
thanks in advance, eddy

[mike.perry]

Original diff for a 1098 LCV is 4.55, 1098 car is 4.22, 1275 would need a 3.9 or 3.7 from Midget.

[bmcecosse]

The 'diff' never changed over the years - the final drive ratio did however - part of which (the crown wheel) is happy bolted to the diff....... So yes - the final drive will cope with a 1275 - for a while anyway! And a nice low 3.7 ratio is ideal for good cruising with a more powerful engine.