I think that it depends on where you'll be racing. You probably don't want to
gear the car so low that you run out of revs in top gear before you have to
start braking at the end of the longest straight. You may want to consider more
than one ratio. I understand the banjo axle can be set up as a
semi-quick-change rear end if you have multiple "pumpkins" set up with
different ratio gear sets to swap out.
Another consideration is that your GT may not be "legal" for whatever
governing body you're vintage racing under, since GTs were only built with
> It looks as though I have found a good banjo rear end for my
> MGB-GT and am now faced with the task of choosing a gear
> ratio. Stock is 3.90, but there are options for 4.30 and
> 4.55. I'm inclined to go with 4.30 unless someone says that
> the 4.55 is really necessary. I'd like the car to be at
> least a little bit streetable when all is said and done, but
> still be best suited for the track. Any input would be
> greatly appreciated.