2nd gen spark plugs in 1st gen RX-7
 

pros/cons?

Anyone do it?

Ive used 3rd gen plugs. The proper heat range is the most important thing, whichever plugs you use.

I've tried 2nd and 3rd (plat's) and I'm back to the originals. From my experiences, the later plugs wore better but fouled easier, at least on my SE. I found that tiny centre electrode was very difficult to clean and deposits formed quickly in this area. I'm sure others have had better results but I wouldn't go back

Hmmm, I'm going to have to try the 3rd gen plugs...maybe coupled with some new wires and 2nd gen coil? I'm on the stock NGK wires, stock coils, but I have the 2nd gen plugs right now...the car idles, runs and revs great....but only compared to my shitty fouled oem plugs.

Ported GSL-SE rotor housings, 86 NA rotors, ported 12A side plates, RB Holley 550 or 600 (not sure), DLIDFIS with GM HEI ignitors and stock coils with an old wire set. BUR7EQ in Leading, BR8EQ-14 in Trailing. It runs awesome!

I used to run 4 trailing 2nd gen plugs, but I couldn't tell any difference.
Search there was a long thread on this about a year ago.