I think I'm probably gonna do 3mm seals. It can't hurt.....can it?

 

I got 150k+ on my stock NA and have no reason to belive it would not make it past 200k no problem, I dont really see any reason for 3mm seals on a NA engine?

 

Truthfully they are over kill however, I think the key to long life is the structurally more stable 2 piece design. I hate the 3 piece seals. Once the top piece gets thin with high mileage, they have a tendency to flip out of the rotor grooves. Plus they carbon freeze easier than the 2 piece. Also the slightest detonation destroys them on higher mileage situations. My NA 91 vert had a rebuilt Mazda reman engine when I bought. The car only had 70k on it with 10k on the rebuild. The rear rotor had no compression. NA rotary's aren't suppose to blow apex seals that early. The car now has 134k and the rear seals are blown again. Car had perfect maintenance too. No oil leaks or over heating with 12k fuel filter and spark plug changes.