According to the Haynes manual, the manual transmission for the Mk 1 is the same, with the same ratios, irrespective of the engine size. Mine does have the steel wheels with 175/65 14 tyres.
Both 4th and 5th gear are technically "overdrive" gears (ratio less than 1), but I find the car very low geared. I am constantly looking for a higher gear when in fact I am in 5th (Top), and have even slipped out of 5th, thinking I was in 3rd, only to have to slip it back in again. I find 1st extremely low (being almost as low as reverse), with a jump to 2nd. I invariably block change past 4th, both changing up as well as down.