The main focus is the installation of the 94+ Miata MX5 gearset, making a relatively close ratio box. Although the earlier Miata transmissions use the same ratios, a dual cone synchro was introduced in 94. With the current age of these cars, used transmissions are readily available so there's no sense using a pre 94 gearset. Quicker cleaner shifts, more time spent closer to peak HP, and fewer shifts in turns are the only advantages to using the Miata gearset. It's no stronger and no more reliable than the FC gearset.