I'm sure this has been listed somewhere before, but here are some ratio numbers for late S1 to S3. They are printed on the speedo face, either above the odometer or under the warning lights.
SWB S1 to S3metric: 1536 - suits 6.00x16 and 6.50x16.
LWB S1: 1500 - suits 7.00x16.
LWB S2 to S3metric: 1408 - suits 7.50x16.
Metric S3 LWB: 860 - suits 7.50x16.
Metric S3 SWB: 880 - suits 6.50x16.
My 2B FC speedo reads 1344 which should suit 9.00x16s. There are some others which I am unfamiliar with but these should help most people.
Dan.
69 2A 88" pet4, 74 3 109" pet4, 68 2B FC pet6.
