Edit:
On second though, you should start with a built engine and a good turbo set-up from ARTech. Everyone deserves a fast Miata, NA is fail/AIDZ.

 

Srsly, U need 2 look @ safety b4 u start adding powah. 1.8L is not safe in 1.6L car. U will shoot ur eye out.

 

hey breh. i heared the 1.6 jdm motors are pretty sik. u shuld get 1 of those. id be tight yo!

..... you didn't say if anything else has been done to your car or not. miata first upgrade = suspension. second upgrade ms.

If your motor has to be rebuilt or replaced... 1.8. you can build whatever motor you want but I wouldn't bother until you upgrade the other stuff first.

If i had to do it again i would have parted out my 1.6 or resold it and bought a 1.8 with good compression and leakdown numbers. around here they can be found in good shape for 3-4k $$$ sell decent shape 1.6 miata $1800ish. you then get better motor, brakes, torsen and didn't even have to go through the hassle of swapping and are around pr @ the same price point. no brainer here speaking from pervious experience. Saw an M addition for 3200 the other day and it was an excellent 95' with 102k miles. made me a little sad. Could have put half the effort into my car and been just as nice and saved myself a couple thousand.

 

---- ripoff sportsmaxx, get genuine rotas!