series 2 gearing

Hi Ive just got a swb series 2 fitted with a 2.8 isuzu diesel fastastic motor but definatly needs the gearing raised as it it very low geared. So what is the cheapest and best way to up the gearing and also is it possable to recalibrate the speedo. (600 x16 wheels fitted but will be changed for 750 x16 so this will help a bit.
Cheers Steve.

Taller tyres or bung an overdrive on it.

or RR or disco diff's.....
i was looking at them higher ratio transfer box gears a whilee ago, might be another option. think it was ashcroft transmissions that did them.

or drive down more hills with the wind behind you!!

i've seen new speedo's drives for taller tyres somewhere but they cost a couple of hundred quid!! i work mine out by judging how fast folk are overtaking.....