Does anyone know what significant accearlation gains I would have, if I replaced my gearbox (1987 Alfa Sprint) to an older sud 1200 5speed closer ratio gearbox?
Regards,
Alex.

Here's a reference to gearbox ratios - http://www.alfa-pages.co.uk/gearbox.htm

We have the short ratio box in our 1.5 Sud used for club sprints, and it's definitely noticeably quicker accelerating out of corners than the longer box.  Great for on the track and not too short that you run out of legs at the end of the straights (well not yet anyway).

On the other hand I used to have a 1.5 Sud Ti with the longer gearbox and the gearing was much nicer for on the road, particularly on the highway at 100kph, revs stay at a reasonable level whereas with the 1.2 box it's over 4000rpm.

Horses for courses I guess...