miata close ratio gear swap
 

http://www.mazdatrix.com/faq/miatainputshaft.htm

anyone have experience with this?
pleased by results?
how about these closer gears with a gtu 4.3 final drive in my N/a?

It's in the archives, also try searching. It's a popular setup with road racers because of the combination of a commonly available close ratio box and the cheapness.

https://www.rx7club.com/2nd-gen-archive-72/miata-transmission-into-na-fc-results-524587/