[HS, YH]

What are the gear ratios and speeds at 8,000 RPM (redline)?

Gear ratios are computed by simply dividing the number of teeth on your spur gear ( larger gear) by the number of teeth on your pinion gear (smaller gear).

R&P stands for Ring and Pinion.  It's the final drive gear for the transaxle -- what is in the differential ("rear end" or "third member") on a conventional front-engine/rear-drive car.

European gears are the same as US for all model years.

* The 4.55 R&P is the only non-OEM one listed here.  It is made by Comptech.

RPM Drop During Upshifts

[KS] You can see from the figures above why the stock '91-94 5-speed has reduced acceleration right after the 1-2 upshift; it's because the revs drop down to 4499, which is where power is significantly reduced from its peak. The  6-speed and the Japanese ("short") gears both get around this by having a lower second gear (i.e. the ratio is numerically higher). Thus the ratio of second gear is closer to first, and the revs only drop to around 5100.

Both the 5-speed and the 6-speed do a great job of keeping the revs in the power band once you get above 100 mph (above third gear), by not letting them drop below the high 6200's, whereas the Japanese gears force the revs to drop to around 5900 with both of the subsequent upshifts. I would expect the numbers to show significantly worse acceleration over 100 mph for the Japanese "short" gears than either the stock 5-speed or the stock 6-speed. The 6-speed would seem to provide the best all-around combination, because it doesn't drop revs too badly at any of the upshifts. It combines the  faster acceleration under 100 mph of the Japanese gears with the faster acceleration over 100 mph of the stock 5-speed gears.

Gear Ratios for Automatic Transmission (all years)