Here are three different combinations of gear ratios and different sizes of tires.
My S2 has an engine I would estimate at somewhere between 105 and 115 horse power. 3.9 diff, semi close gear box and Sumitomo 200HTR 175/70-13 tires. Good for acceleration from a start, but needs a taller 1st for my liking. High speed cruising sucks.
My Plus2 has had three different setups. All have been with the 2L Zetec, 45 DCOE equipped, horsepower estimated around 160, torque unknown, lightweight Fidanza aluminum flywheel, Vredestine 165-13 tires. Started with a 3.77 and the semi close ratio. Enough torque to easily spin the tires on a quick takeoff, but ran out of gear way too soon. Changed to a 3.54 diff, everything else stayed the same. Less of a chance at spinning the tires on takeoff, but still ran out of gear early. Cruising rpm better, but acceleration rate dropped off, but still acceptable. Changed to a close ratio, stayed with the 3.54 diff. This combination is a bit more difficult to get off the line, but with the torque, it is totally manageable. Gets out of my steep driveway up to the road with no difficulty, even when the engine is cold. Love the long legged 1st gear, 6500 rpm is 52 mph.
My Sabra GT has a 100 horsepower engine with a very heavy stock iron flywheel, close ratio ZF (same ratios as CR 2000E), Vredestine 165-15 tires, and a 3.55 diff, about 150 lbs lighter than the Plus2. The maximum rpm of this engine is 5000 rpm, so even thought it has more mph per rpm in 1st gear, it will not stretch as far. This car is at its limit with the standard combination of gearing. Doesn’t like climbing out of my driveway, or getting started going up hill from a stop, Takes a bunch of rpm and quick action with the accelerator/brake/clutch action. Without the heavy flywheel, it would be nearly impossible. The E brake is handy and is used on an uphill start. Almost all slow driving is in 2nd or 3rd gear. Not enough hp or torque for easy driving.
If I had a choice (read money), I would have a 5-speed with the close ratios in both, along with a .82 fifth. Would put the 3.77 in the S2 and leave the 3.54 in the P2. The Sabra will stay the same, and it has a more relaxed highway cruising. Eighty mph is quite pleasant. The larger diameter tires make it like being in overdrive all the time.