Will NB 6-speed manual transmission (with NB shifter) fit a Mazda Miata NA (1990-1997)?
Fits with extra parts or work. Confirmed
| Part | NB 6-speed manual transmission (with NB shifter) |
|---|---|
| Vehicle | Mazda Miata NA (1990-1997) |
| Years | 1990-1997 |
| Trim / condition | manual NA |
| Status | confirmed |
| Confidence | 3 of 3 — Backed by a manufacturer document, or two or more independent sources agree on a specific checkable fact. |
Notes
Two sources agree the NB 6-speed bolts into a manual NA. You need the 6-speed donor's trans plate and shifter, the NA speedometer gear/cable replaces the NB electronic sensor, and only two of the three starter bolts are used. Gearing: the 6-speed is much steeper and in the US was paired with a 3.909 rear; one source says a 4.30 rear should be changed to 3.909 or at least 4.10.
Specs
- ratios: 3.76/2.269/1.645/1.257/1.00/0.843
- note: US 6-speed paired with 3.909 rear
Sources
- Miata Drivetrain Interchange Guide — Randy Stocker / SoloMiata (fixjunk.com) (editorial; read 2026-10-15; full page read)
- NB to NA Miata Compatibility Guide — Redline Auto Parts (used-parts dealer; hands-on checks, own disclaimer) (vendor article; read 2026-10-15; full page read)
See also this part across generations: NB 6-speed manual transmission (with NB shifter). Fitment is not guaranteed — disclaimer.