Yeah, the mk2 172 has a closer ratio gearbox than a mk1 172.
This is one thing I noticed the other night when I was driving the Cup and the mk2, as Id previously only ever driven a mk1.
Now, dont know exactly whats different, whether its the individual gears or just the final drive ratio, but there is a difference.
Would be a good idea to do an rpm vs speed comparison for the mk1 and mk2 then youll get an idea of the differences...