If you're hell-bent on swapping a motor for some reason.... the LSx is really the only one that "makes sense."

SR20 swaps are dumb.

Rotaries are cool, but no real payoff beyond DAT BRAP BRAP BRAP and being able to tell someone you swapped your motor.

The KL swap is an engineering circle jerk with potential for HUGE power, but it's not so well supported, and if you're asking the original question, a KL swap is not within your grasp.

The Mazdaspeed Turbo swap is dumb. Turbo your existing motor and voila! You've got a Mazdaspeed Turbo motor, but better!

The 5.0 swap is mostly irrelevant at this point in time with the support of the LSx swaps in my opinion.

FE3 swap is cool, but again, is it really worth doing over just boosting a BP? Meh.



Basically, the only logical choices when it comes to making more power in a Miata are 1) Turbo BP, or 2) LSx swap.



Do as i say, not as i do.

<---- F2T swap incoming.