Diff 3:54 vs 3:31

[christopher storey]

Ideally yes ( and BTW it is 1120 not 1125 tpm for a 3.07) but if you send your speedo off to someone like Speedograph Richfield in Nottingham they will be able to recalibrate it for you and in all probability change the odometer gears to suit as well. It's best to get instructions from them beforehand as to what information they need - usually it invoves rolling the car forward a set distance , counting the turns of the speedo cable as you do so, and giving them tyre diameter info